bugfix for win trees when using "stay in current win" command variants

Previously maps like T would not restore the cursor position. Not sure
why the code was like this in the first place... hopefully I haven't
just broken a bunch of shit.

Closes #146.

lib/nerdtree/opener.vim

@@ -247,16 +247,9 @@ function! s:Opener._openFile()
     endif
 
     call self._gotoTargetWin()
-
-    if self._nerdtree.isWinTree()
-        call self._path.edit()
-    else
-        call self._path.edit()
-
-
-        if self._stay
-            call self._restoreCursorPos()
-        endif
+    call self._path.edit()
+    if self._stay
+        call self._restoreCursorPos()
     endif
 endfunction