fixes a regression since UIDL refactoring (non-hosted mode only)

svn changeset:8544/svn branch:6.1

src/com/vaadin/terminal/gwt/client/UIDL.java

     }
 
     public boolean hasVariable(String name) {
-        return var().containsKey(name);
+        return hasVariables() && var().containsKey(name);
     }
 
     public String getStringVariable(String name) {

src/com/vaadin/terminal/gwt/client/ui/VTextField.java

             setColumns(new Integer(uidl.getStringAttribute("cols")).intValue());
         }
 
-        String text = uidl.getStringVariable("text");
+        String text = uidl.hasVariable("text") ? uidl.getStringVariable("text")
+                : null;
         setPrompting(inputPrompt != null && focusedTextField != this
                 && (text == null || text.equals("")));
         if (prompting) {