move maintainClipboard into if block

src/text-editor.coffee

@@ -2594,7 +2594,7 @@ class TextEditor extends Model
     for selection in @getSelectionsOrderedByBufferPosition()
       if not selection.isEmpty()
         selection.copy(maintainClipboard, true)
-      maintainClipboard = true
+        maintainClipboard = true
     return
 
   # Essential: For each selection, cut the selected text.