Keystone Internal Server Error (HTTP 500) after apache restart when influxdb is installed

When influxdb is installed, a Internal Server Error is shown with this trace in /var/log/apache2/keystone.log after executing systemctl restart apache2.
Influxdb version is- 1.3.5
Logs:
2017-08-30 17:32:36.492291 OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/urllib3-1.22.dist-info'
2017-08-30 17:33:15.741127 mod_wsgi (pid=3736): Target WSGI script '/usr/bin/keystone-wsgi-public' cannot be loaded as Python module.
2017-08-30 17:33:15.741187 mod_wsgi (pid=3736): Exception occurred processing WSGI script '/usr/bin/keystone-wsgi-public'.
2017-08-30 17:33:15.741218 Traceback (most recent call last):
2017-08-30 17:33:15.741235 File "/usr/bin/keystone-wsgi-public", line 6, in
2017-08-30 17:33:15.741295 from keystone.server.wsgi import initialize_public_application
2017-08-30 17:33:15.741306 File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 18, in
2017-08-30 17:33:15.741360 from oslo_log import log
2017-08-30 17:33:15.741369 File "/usr/lib/python2.7/dist-packages/oslo_log/log.py", line 42, in
2017-08-30 17:33:15.741467 from oslo_config import cfg
2017-08-30 17:33:15.741476 File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 458, in
2017-08-30 17:33:15.742008 import debtcollector
2017-08-30 17:33:15.742031 File "/usr/lib/python2.7/dist-packages/debtcollector/init.py", line 15, in
2017-08-30 17:33:15.742077 import pbr.version
2017-08-30 17:33:15.742087 File "/usr/lib/python2.7/dist-packages/pbr/version.py", line 25, in
2017-08-30 17:33:15.742198 import pkg_resources
2017-08-30 17:33:15.742208 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 3019, in
2017-08-30 17:33:15.742784 @_call_aside
2017-08-30 17:33:15.742801 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 3003, in _call_aside
2017-08-30 17:33:15.742819 f(*args, **kwargs)
2017-08-30 17:33:15.742841 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 3032, in _initialize_master_working_set
2017-08-30 17:33:15.742852 working_set = WorkingSet._build_master()
2017-08-30 17:33:15.742858 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 646, in _build_master
2017-08-30 17:33:15.742867 ws = cls()
2017-08-30 17:33:15.742872 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 639, in init
2017-08-30 17:33:15.742879 self.add_entry(entry)
2017-08-30 17:33:15.742884 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 695, in add_entry
2017-08-30 17:33:15.742892 for dist in find_distributions(entry, True):
2017-08-30 17:33:15.742897 File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 2012, in find_on_path
2017-08-30 17:33:15.742905 if len(os.listdir(fullpath)) == 0: