fix default value

Author: russelmrcl

core/src/main/java/com/predic8/membrane/core/interceptor/flow/IfInterceptor.java

@@ -100,7 +100,7 @@ public Language getLanguage() {
 
     /**
      * @description Language of the 'test' condition
-     * @default groovy
+     * @default SpEL
      * @example SpEL, groovy, jsonpath, xpath
      */
     @MCAttribute