Update ConfigurationMethod.java - remove extra whitespace in log

This change removes an extra whitespace character that is part of a warning message that is logged when static methods are used for Test suite configuration.

testng-core/src/main/java/org/testng/internal/ConfigurationMethod.java

@@ -164,7 +164,7 @@ private static ITestNGMethod[] createMethods(
             "Detected a static method ["
                 + method.getQualifiedName()
                 + "()]. Static configuration methods can cause "
-                + " unexpected behavior.";
+                + "unexpected behavior.";
         Logger.getLogger(Configuration.class).warn(msg);
       }