Fixed Chinese constellation boundaries.

[sunshuwei]

Fixed Chinese constellation boundaries.

Issue: when the "Select single constellation" option is selected, the constellation boundaries will be misaligned and and the adjacent constellation will be displayed.

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching skycultures/**:

• Did you remember to update po/stellarium-skycultures/POFILES.in and src/translations.h files respectively to changes in sky cultures?
• Did you remember to update skycultures/CMakeLists.txt and skycultures/YOUR-SKYCULTURE-FOLDER/CMakeLists.txt files respectively to changes in sky cultures?
• Did you remember to update util/skycultures/po4a.config file respectively to changes in sky cultures?
• Did you remember to define classification parameter in sky cultures?

This is an automatically generated QA checklist based on modified files

[alex-w]

Thanks!