Improved exception message. This should allow users who add whitespace to easily see that they've made a mistake.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/logging/trunk@372295 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/logging/impl/LogFactoryImpl.java

@@ -715,8 +715,8 @@ public class LogFactoryImpl extends LogFactory {
                                         true);
             if (result == null) {
                 throw new LogConfigurationException(
-                        "User-specified log class " + specifiedLogClassName
-                        + " cannot be found or is not useable.");
+                        "User-specified log class '" + specifiedLogClassName
+                        + "' cannot be found or is not useable.");
             }
             
             return result;