Fix file permission of non-executable files

[wangruohui]

Non-executable files should be of file permission 644.
This can be done in Minux of Mac by chmod 644 path_to_tile or in batch by find . -type f | xargs chmod 644 .

[codecov]

Codecov Report

Merging #718 (6b56e49) into master (8043791) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #718      +/-   ##
==========================================
+ Coverage   81.80%   81.81%   +0.01%     
==========================================
  Files         211      211              
  Lines       11896    11896              
  Branches     1912     1912              
==========================================
+ Hits         9731     9733       +2     
+ Misses       1869     1868       -1     
+ Partials      296      295       -1     

Flag	Coverage Δ
unittests	81.79% <ø> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
mmedit/models/backbones/sr_backbones/rrdb_net.py	95.83% <ø> (ø)
...ls/components/stylegan2/generator_discriminator.py	86.14% <0.00%> (+1.20%)	⬆️

---

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 8043791...6b56e49. Read the comment docs.