fix: fix checkstyle error

Author: S-furi

alchemist-implementationbase/src/main/java/it/unibo/alchemist/model/reactions/AbstractReaction.java

@@ -411,7 +411,7 @@ protected final void setOutputContext(final Context c) {
 
     /**
      * @return the default implementation returns a String in the form
-     * className@timeScheduled[Conditions]-rate->[Actions]
+     *      className@timeScheduled[Conditions]-rate->[Actions]
      */
     @Override
     public String toString() {