Fix select fields regression on master backlog/taskboard after merging …

…#942.

Added check to ensure default select value does not override values of existing stories/tasks.

assets/javascripts/model.js

@@ -119,9 +119,12 @@ RB.Model = RB.Object.create({
 
       // Copy the value in the field to the input element
       value = ( fieldType=='select' ? field.children('.v').first().text() : RB.$.trim(field.text()) );
-      if ((fieldType=='select') && input.children("option[selected='selected']")) {
+
+      // Select default value for select fields if none is already selected
+      if ((fieldType=='select') && input.children("option[selected='selected']") && value == '') {
     	  value = input.children("option[selected='selected']:first").val();
       }
+
       input.val(value);
 
       // Record in the model's root element which input field had the last focus. We will