Ensured correct message assertion on all JDKs (value was different on JDK 15 and later)

Author: lhazlewood

README.md

@@ -152,7 +152,7 @@ enforcement.
  * Convenient and readable [fluent](http://en.wikipedia.org/wiki/Fluent_interface) interfaces, great for IDE 
    auto-completion to write code quickly
  * Fully RFC specification compliant on all implemented functionality, tested against RFC-specified test vectors
- * Stable implementation with over 1,100+ tests and enforced 100% test code coverage.  Every single method, statement 
+ * Stable implementation with over 1,200+ tests and enforced 100% test code coverage.  Every single method, statement 
    and conditional branch variant in the entire codebase is tested and required to pass on every build.
  * Creating, parsing and verifying digitally signed compact JWTs (aka JWSs) with all standard JWS algorithms: