error message fixed

Author: thurka

visualvm/libs.profiler/profiler.oql/src/org/graalvm/visualvm/lib/profiler/oql/engine/api/impl/OQLEngineImpl.java

@@ -218,7 +218,7 @@ private void executeQuery(OQLQueryImpl q, ObjectVisitor visitor)
 
             clazz = snapshot.findClass(className);
             if (clazz == null) {
-                throw new OQLException(className + " is not found!"); // NOI18N
+                throw new OQLException(className + " was not found!"); // NOI18N
             }
         }