wxPython 4/cursor manager/Find dialog: use sizer.Add instead of sizer…

….AddSizer. re nvaccess#7077.

source/cursorManager.py

@@ -1,6 +1,6 @@
 #cursorManager.py
 #A part of NonVisual Desktop Access (NVDA)
-#Copyright (C) 2006-2016 NV Access Limited, Joseph Lee, Derek Riemer
+#Copyright (C) 2006-2017 NV Access Limited, Joseph Lee, Derek Riemer
 #This file is covered by the GNU General Public License.
 #See the file COPYING for more details.
 
@@ -49,7 +49,7 @@ def __init__(self, parent, cursorManager, text, caseSensitivity):
 		self.caseSensitiveCheckBox.SetValue(caseSensitivity)
 		mainSizer.Add(self.caseSensitiveCheckBox,border=10,flag=wx.BOTTOM)
 
-		mainSizer.AddSizer(self.CreateButtonSizer(wx.OK|wx.CANCEL), flag=wx.ALIGN_RIGHT)
+		mainSizer.Add(self.CreateButtonSizer(wx.OK|wx.CANCEL), flag=wx.ALIGN_RIGHT)
 		self.Bind(wx.EVT_BUTTON,self.onOk,id=wx.ID_OK)
 		self.Bind(wx.EVT_BUTTON,self.onCancel,id=wx.ID_CANCEL)
 		mainSizer.Fit(self)