Remove "total_authors = 0" fallback.

When counting authors, do not fall back to 0 if the git call fails. Zero
authors causes ZeroDivisionError later on otherwise. This reverts an old change
for msysgit on win32, introduced in a01045f2480a21f28dd90e278b4f560020a97b9e.
It should no longer be necessary.

gitstats

 	def collect(self, dir):
 		DataCollector.collect(self, dir)
 
-		try:
-			self.total_authors += int(getpipeoutput(['git shortlog -s %s' % getcommitrange(), 'wc -l']))
-		except:
-			self.total_authors = 0
+		self.total_authors += int(getpipeoutput(['git shortlog -s %s' % getcommitrange(), 'wc -l']))
 		#self.total_lines = int(getoutput('git-ls-files -z |xargs -0 cat |wc -l'))
 
 		# tags