Don't sign git tags (haikuports#283)

Rationale: when the git config setting `tag.gpgSign=true` is used, this implies the `-s` option to
`git tag`. This means that git needs a message for the tag. Because no message is given, git
invokes an editor, which doesn't work when running non-interactively.

We don't need signed tags in a git repo created by HaikuPorter, so the easiest solution is to pass
`--no-sign` to `git tag` calls.

HaikuPorter/Source.py

@@ -399,7 +399,7 @@ def commitPatchPhase(self):
 		output = check_output(['git', 'commit', '-a', '-q', '-m', 'patch function'],
 				   cwd=self.sourceDir, env=self.gitEnv).decode('utf-8')
 		info(output)
-		output = check_output(['git', 'tag', '-f', 'PATCH_FUNCTION', 'HEAD'],
+		output = check_output(['git', 'tag', '--no-sign', '-f', 'PATCH_FUNCTION', 'HEAD'],
 				   cwd=self.sourceDir).decode('utf-8')
 		info(output)
 
@@ -508,7 +508,8 @@ def _initImplicitGitRepo(self):
 		info(check_output(['git', 'add', '-f', '.'], cwd=self.sourceDir).decode('utf-8'))
 		info(check_output(['git', 'commit', '-m', 'import', '-q'],
 				   cwd=self.sourceDir, env=self.gitEnv).decode('utf-8'))
-		info(check_output(['git', 'tag', 'ORIGIN'], cwd=self.sourceDir).decode('utf-8'))
+		info(check_output(['git', 'tag', '--no-sign', 'ORIGIN'],
+				   cwd=self.sourceDir).decode('utf-8'))
 
 	def _isInGitWorkingDirectory(self, path):
 		"""Returns whether the given source directory path is in a git working