[MNG-8545] Use of RemoteRepository in keys w/o equals/hashes (#2064)

But they have no hash/equals defined.

---

https://issues.apache.org/jira/browse/MNG-8545

Author: cstamas

impl/maven-impl/src/main/java/org/apache/maven/impl/DefaultRemoteRepository.java

@@ -18,6 +18,8 @@
  */
 package org.apache.maven.impl;
 
+import java.util.Objects;
+
 import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.annotations.Nonnull;
 
@@ -56,6 +58,16 @@ public String getProtocol() {
         return repository.getProtocol();
     }
 
+    @Override
+    public boolean equals(Object o) {
+        return o instanceof DefaultRemoteRepository that && Objects.equals(repository, that.repository);
+    }
+
+    @Override
+    public int hashCode() {
+        return repository.hashCode();
+    }
+
     @Override
     public String toString() {
         return repository.toString();