Fix "Prefer format() over string interpolation operator" issue

[nijel]

This pull request automatically fixes all occurrences of the following issue:

Issue type: Prefer format() over string interpolation operator
Issue details: https://www.quantifiedcode.com/app/project/gh:gammu:python-gammu?groups=code_patterns/%3A4ACGxFj1

To adjust the commit message or the actual code changes, just rebase or cherry-pick the commits.
For questions or feedback reach out to cody@quantifiedcode.com.

Legal note: We won't claim any copyrights on the code changes.

Cheers,
Cody - Your code quality bot

[coveralls]

Coverage remained the same at 38.595% when pulling 7dbec7b on autofix/wrapped2_to3_fix into 35c8678 on master.

[codecov-io]

Codecov Report

Merging #18 into master will not change coverage.
The diff coverage is 1.47%.

@@           Coverage Diff           @@
##           master      #18   +/-   ##
=======================================
  Coverage   37.69%   37.69%           
=======================================
  Files          46       46           
  Lines        1666     1666           
  Branches      203      203           
=======================================
  Hits          628      628           
  Misses       1023     1023           
  Partials       15       15

Impacted Files	Coverage Δ
examples/worker.py	0% <ø> (ø)	✅
test/test_smsd.py	84.61% <ø> (ø)	✅
examples/addcontacts.py	0% <ø> (ø)	✅
examples/getallcalendar.py	0% <ø> (ø)	✅
examples/getallmemory_nonext.py	0% <ø> (ø)	✅
gammu/worker.py	87.69% <ø> (ø)	✅
examples/getalltodo.py	0% <ø> (ø)	✅
examples/incoming.py	0% <ø> (ø)	✅
examples/read_sms_backup.py	0% <ø> (ø)	✅
examples/getallsms.py	0% <ø> (ø)	✅
... and 10 more

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