fix stupid bug return false instead of null for errors on get

Author: gwhalin

src/com/danga/MemCached/MemCachedClient.java

@@ -19,7 +19,7 @@
  * @author Kevin Burton <[email protected]>
  * @author Robert Watts <[email protected]>
  * @author Vin Chawla <[email protected]>
- * @version 1.5.2
+ * @version 1.6.1
  */
 package com.danga.MemCached;
 
@@ -1200,7 +1200,7 @@ public Object get( String key, Integer hashCode, boolean asString ) {
 				errorHandler.handleErrorOnGet( this, e, key );
 
 			log.error( "failed to sanitize your key!", e );
-			return false;
+			return null;
 		}
 
 		// get SockIO obj using cache key