Issue #16511: Use default IDLE width and height if config param is not valid.

Patch Serhiy Storchaka.
diff --git a/Lib/idlelib/configDialog.py b/Lib/idlelib/configDialog.py
index 9884d5e..b707fc3 100644
--- a/Lib/idlelib/configDialog.py
+++ b/Lib/idlelib/configDialog.py
@@ -947,7 +947,7 @@
             self.listFontName.select_anchor(currentFontIndex)
         ##font size dropdown
         fontSize=idleConf.GetOption('main','EditorWindow','font-size',
-                default='10')
+                type='int', default='10')
         self.optMenuFontSize.SetMenu(('7','8','9','10','11','12','13','14',
                 '16','18','20','22'),fontSize )
         ##fontWeight
@@ -1033,10 +1033,13 @@
         self.autoSave.set(idleConf.GetOption('main', 'General', 'autosave',
                                              default=0, type='bool'))
         #initial window size
-        self.winWidth.set(idleConf.GetOption('main','EditorWindow','width'))
-        self.winHeight.set(idleConf.GetOption('main','EditorWindow','height'))
+        self.winWidth.set(idleConf.GetOption('main','EditorWindow','width',
+                                             type='int'))
+        self.winHeight.set(idleConf.GetOption('main','EditorWindow','height',
+                                              type='int'))
         #initial paragraph reformat size
-        self.paraWidth.set(idleConf.GetOption('main','FormatParagraph','paragraph'))
+        self.paraWidth.set(idleConf.GetOption('main','FormatParagraph','paragraph',
+                                              type='int'))
         # default source encoding
         self.encoding.set(idleConf.GetOption('main', 'EditorWindow',
                                              'encoding', default='none'))