Set version to 1.9.0.RC1

org.aspectj.ajdt.core/src/org/aspectj/ajdt/ajc/messages.properties

@@ -4,7 +4,7 @@
      The -Xlintfile:lint.properties allows fine-grained control. In tools.jar, see
      org/aspectj/weaver/XlintDefault.properties for the default behavior and a template to copy. 
 ### AspectJ-specific messages 
-compiler.name = AspectJ Compiler 1.9.0
+compiler.name = AspectJ Compiler 1.9.0.RC1
 compiler.version = Eclipse Compiler BETA_JAVA9_062ac5d7a6bf9(Sep2017), 3.13
 compiler.copyright =