GremlinQueryCreator.java::toCondition() should not change member field 'schema'

[kerler]

org.springframework.data.gremlin.query.GremlinQueryCreator.java::toCondition() changes member field 'schema', as make that sometimes GremlinQueryCreator.java::complete() uses member field 'schema' whose value is different against what is set in constructor.

Suggest to define all the member field of GremlinQueryCreator.java to be final, and in toCondition() use a local variable such like 'GremlinSchema tmpSchema = this.schema;'.