Fix errors and reinstall if necessary

We are trying to install this software https://github.com/WessexWater/chellow

Three freelancers already tried to install this software, only bid if you understand whats needs to be done, below are some of the errors we faced.

ERROR:sqlalchemy.pool.impl.QueuePool:Exception closing connection <pg8000.legacy.Connection object at 0x7f4c70cca0b8>
Traceback (most recent call last):
File "/usr/local/lib/python3.6/dist-packages/chellow/proxy.py", line 38, in __call__
x_proto = environ["HTTP_X_FORWARDED_PROTO"]
KeyError: 'HTTP_X_FORWARDED_PROTO'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.6/dist-packages/pg8000/core.py", line 271, in sock_flush
self._sock.flush()
File "/usr/lib/python3.6/socket.py", line 604, in write
return self._sock.send(b)
OSError: [Errno 88] Socket operation on non-socket

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 1707, in _execute_context
cursor, statement, parameters, context
File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/default.py", line 716, in do_execute
cursor.execute(statement, parameters)
File "/usr/local/lib/python3.6/dist-packages/pg8000/legacy.py", line 245, in execute
self._c.execute_unnamed("begin transaction")
File "/usr/local/lib/python3.6/dist-packages/pg8000/core.py", line 640, in execute_unnamed
self._flush()
File "/usr/local/lib/python3.6/dist-packages/pg8000/core.py", line 273, in sock_flush
raise InterfaceError("network error on flush") from e
pg8000.exceptions.InterfaceError: network error on flush

The above exception was the direct cause of the following exception:

Traceback (most recent call last):