Updated failure_list_java.txt for Java conformance test

A new test is now passing and so we can remove it from the failure
whitelist.

conformance/failure_list_java.txt

@@ -32,7 +32,6 @@ Recommended.JsonInput.StringFieldSingleQuoteValue
 Recommended.JsonInput.StringFieldSurrogateInWrongOrder
 Recommended.JsonInput.StringFieldUnpairedHighSurrogate
 Recommended.JsonInput.StringFieldUnpairedLowSurrogate
-Recommended.JsonInput.StringFieldUppercaseEscapeLetter
 Recommended.JsonInput.Uint32MapFieldKeyNotQuoted
 Recommended.JsonInput.Uint64MapFieldKeyNotQuoted
 Required.JsonInput.EnumFieldNotQuoted