Use 0 not False to disable checkChecksums as documented and used

While False does get the job done, the value is not always treated as
a boolean. It is overloaded so that 1 or greater is True, but more than
1 has a different meaning than 1. Hence usage should always be as an
integer as documented so that it's clear(er) this isn't just an on/off
toggle.

Lib/fontTools/subset/__init__.py

@@ -2711,7 +2711,7 @@ class Subsetter(object):
 def load_font(fontFile,
 	      options,
 	      allowVID=False,
-	      checkChecksums=False,
+	      checkChecksums=0,
 	      dontLoadGlyphNames=False,
 	      lazy=True):
 

Lib/fontTools/ttLib/ttFont.py

@@ -18,7 +18,7 @@ class TTFont(object):
 	"""
 
 	def __init__(self, file=None, res_name_or_index=None,
-			sfntVersion="\000\001\000\000", flavor=None, checkChecksums=False,
+			sfntVersion="\000\001\000\000", flavor=None, checkChecksums=0,
 			verbose=None, recalcBBoxes=True, allowVID=False, ignoreDecompileErrors=False,
 			recalcTimestamp=True, fontNumber=-1, lazy=None, quiet=None,
 			_tableCache=None):