Remove unused variables in the code

This commit removes unused variables or rename variables as "expected to
be unused" by using "_" prefix.

This covers only cases where fix was easy or only one unused variable
was in a module

Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

ipapython/nsslib.py

@@ -234,7 +234,7 @@ class NSSConnection(httplib.HTTPConnection, NSSAddressFamilyFallback):
         self.sock.set_ssl_option(ssl.SSL_HANDSHAKE_AS_CLIENT, True)
         try:
             self.sock.set_ssl_version_range(self.tls_version_min, self.tls_version_max)
-        except NSPRError as e:
+        except NSPRError:
             root_logger.error('Failed to set TLS range to %s, %s' % (self.tls_version_min, self.tls_version_max))
             raise
         self.sock.set_ssl_option(ssl_require_safe_negotiation, False)