ssh, sudo: Remove redundant else clause on bootstrap loop

Since the for loops don't contain any break statements the StreamErrors
will always be raised when the loop completes without the method
resturning.

See https://lgtm.com/rules/5980098/

Refs #61

mitogen/ssh.py

@@ -126,5 +126,4 @@ class Stream(mitogen.parent.Stream):
                 LOG.debug('sending password')
                 self.transmit_side.write(self.password + '\n')
                 password_sent = True
-        else:
-            raise mitogen.core.StreamError('bootstrap failed')
+        raise mitogen.core.StreamError('bootstrap failed')

mitogen/sudo.py

@@ -107,5 +107,4 @@ class Stream(mitogen.parent.Stream):
                 LOG.debug('sending password')
                 os.write(self.transmit_side.fd, self.password + '\n')
                 password_sent = True
-        else:
-            raise mitogen.core.StreamError('bootstrap failed')
+        raise mitogen.core.StreamError('bootstrap failed')