*)fixed error when setting empty language/skin

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2016 6c8d7289-2bf4-0310-a012-ef5d649a1542

htroot/ConfigLanguage_p.java

@@ -83,7 +83,7 @@ public class ConfigLanguage_p {
 	
 	if (post != null){
 		//change language
-		if(post.containsKey("use_button")){
+		if(post.containsKey("use_button") && (String)post.get("lang") != null){
 			translator.changeLang(env, langPath, (String)post.get("lang"));
 			
 		//delete language file

htroot/ConfigSkins_p.java

@@ -112,7 +112,7 @@ public class ConfigSkins_p {
 	
 	if (post != null){
 		//change skin
-		if(post.containsKey("use_button")){
+		if(post.containsKey("use_button") && (String)post.get("skin") != null){
 			changeSkin(switchboard, skinPath, (String)post.get("skin"));
 			
 		//delete skin