refurbish code PEP8 & Co./wap_client

Summary:
PEP8:
E302 expected 2 blank lines
E201 + E202 + E231 Whitespaces

Comparison with None performed with equality operators
+ E714 is not
+ E711

redundant Paranthesis

Reviewers: PyKolab Developers, sicherha

Reviewed By: PyKolab Developers, sicherha

Subscribers: sicherha

Differential Revision: https://git.kolab.org/D3779