Minor cosmetics

[bernhardkaindl]

Four minor cosmetic updates:

• xcp/pci.py: Fix pylint Unnecessary parens after 'not' keyword

  • Fix pylint warning superfluous-parens (Unnecessary parens after 'not')

• xcp/version.py: Add missing type annotations and merge asserts

• xcp/xmlunwrap.py: Fix false positive from raise in six.raise_from()

• stubs/pytest_httpserver.pyi: Silence pylint warnings

[codecov]

Codecov Report

Merging #112 (345a5df) into master (c734982) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #112      +/-   ##
==========================================
- Coverage   82.73%   82.72%   -0.02%     
==========================================
  Files          21       21              
  Lines        3371     3369       -2     
==========================================
- Hits         2789     2787       -2     
  Misses        582      582              

Flag	Coverage Δ
unittest	82.72% <100.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
xcp/mount.py	58.33% <100.00%> (-0.86%)	⬇️
xcp/pci.py	86.51% <100.00%> (ø)
xcp/version.py	100.00% <100.00%> (ø)
xcp/xmlunwrap.py	96.22% <100.00%> (ø)