SchemaDiff reports incorrect breakage count #2877

Describe the bug
The SchemaDiff$CountingReporter reports a different breakingCount compared to the CapturingReporter.getBreakageCount().
I'm fairly certain its breakingCount field should be initialised with 0: https://github.com/graphql-java/graphql-java/blob/master/src/main/java/graphql/schema/diff/SchemaDiff.java#L73

To Reproduce
Given the following code:

var capturingReporter = new CapturingReporter();
var schemaDiff = new SchemaDiff();
var schema = <some GraphQLSchema>;

int breakingCount = schemaDiff.diffSchema(DiffSet.diffSet(schema, schema), capturingReporter);

System.out.println(breakingCount + " != " + capturingReporter.getBreakageCount());

this will print 1 != 0

This also means that if you use the return value of the schemaDiff method to assert no breaking changes with breakingCount == 0, this will always fail.