fix the case of the number of male/female executive is zero

[peisuke]

Fixed the problem of the title.

• unsupported operand type(s) exception occurs If the number of male/female executives is zero. #1

Before adding the value, the new codes checks the type.

[codecov-io]

Codecov Report

Merging #2 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master       #2      +/-   ##
==========================================
+ Coverage   91.97%   91.98%   +<.01%     
==========================================
  Files          27       27              
  Lines        1084     1085       +1     
==========================================
+ Hits          997      998       +1     
  Misses         87       87

Impacted Files	Coverage Δ
xbrr/edinet/reader/aspects/information.py	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5aae86c...dcb3294. Read the comment docs.

[icoxfog417]

Thank you! I want to support Kanji number someday.