Supplementary view invalidation issues

[chrisballinger]

cc @N-Pex

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x00000000 at 0x0000000000000000
Crashed Thread:  0

Application Specific Information:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'layout attributes for supplementary item at index path (<NSIndexPath: 0xc000000000000016> {length = 2, path = 0 - 0}) changed from <JSQMessagesCollectionViewLayoutAttributes: 0x1068922a0> index path: (<NSIndexPath: 0xc000000000000016> {length = 2, path = 0 - 0}); element kind: (UICollectionElementKindSectionHeader); frame = (0 0; 375 32); zIndex = 10;  to <JSQMessagesCollectionViewLayoutAttributes: 0x1068f4cd0> index path: (<NSIndexPath: 0xc000000000000016> {length = 2, path = 0 - 0}); element kind: (UICollectionElementKindSectionHeader); frame = (0 0; 375 32); zIndex = -1;  without invalidating the layout'

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   CoreFoundation                  0x00000001835f7164 __exceptionPreprocess + 124
1   libobjc.A.dylib                 0x0000000182840528 objc_exception_throw + 52
2   CoreFoundation                  0x00000001835f7038 +[NSException raise:format:arguments:] + 100
3   Foundation                      0x0000000183f917f4 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 108
4   UIKit                           0x000000018cc0d40c __45-[UICollectionViewData validateLayoutInRect:]_block_invoke + 1496
5   UIKit                           0x000000018cc0c888 -[UICollectionViewData validateLayoutInRect:] + 1496
6   UIKit                           0x000000018d691cc4 -[UICollectionViewData layoutAttributesForCellsInRect:validateLayout:] + 144
7   UIKit                           0x000000018d63c034 -[UICollectionView _computePrefetchCandidatesForVisibleBounds:futureVisibleBounds:prefetchVector:notifyDelegateIfNeeded:] + 128
8   UIKit                           0x000000018d63bf94 -[UICollectionView _computePrefetchCandidatesForVelocity:notifyDelegateIfNeeded:] + 164
9   UIKit                           0x000000018d63bec4 -[UICollectionView _prefetchItemsForVelocity:maxItemsToPrefetch:invalidateCandidatesOnDirectionChanges:] + 756
10  UIKit                           0x000000018cc0bec8 -[UICollectionView layoutSubviews] + 768
11  UIKit                           0x000000018cbaee18 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1272
12  QuartzCore                      0x000000018763b948 -[CALayer layoutSublayers] + 180
13  QuartzCore                      0x000000018763fad0 CA::Layer::layout_if_needed(CA::Transaction*) + 328
14  QuartzCore                      0x00000001875ac31c CA::Context::commit_transaction(CA::Transaction*) + 332
15  QuartzCore                      0x00000001875d3b40 CA::Transaction::commit() + 536
16  QuartzCore                      0x000000018752574c CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 924
17  IOKit                           0x0000000183862098 IODispatchCalloutFromCFMessage + 388
18  CoreFoundation                  0x0000000183585090 __CFMachPortPerform + 184
19  CoreFoundation                  0x000000018359fe00 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
20  CoreFoundation                  0x000000018359f504 __CFRunLoopDoSource1 + 436
21  CoreFoundation                  0x000000018359cfd8 __CFRunLoopRun + 2192
22  CoreFoundation                  0x00000001834bcc58 CFRunLoopRunSpecific + 432
23  GraphicsServices                0x0000000185368f84 GSEventRunModal + 96
24  UIKit                           0x000000018cc155c4 UIApplicationMain + 232
25  ChatSecure                      0x0000000102fbfd30 main (AppDelegate.swift:14)
26  libdyld.dylib                   0x0000000182fdc56c start + 0