Don't write to log NoCommitterAccount

[thehowl]

It's way too verbose, and the information is also printed to the user
already. Fixes #3602.

[codecov-io]

Codecov Report

Merging #3621 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #3621      +/-   ##
==========================================
- Coverage   36.15%   36.14%   -0.01%     
==========================================
  Files         285      285              
  Lines       40921    40924       +3     
==========================================
  Hits        14794    14794              
- Misses      23953    23957       +4     
+ Partials     2174     2173       -1

Impacted Files	Coverage Δ
models/gpg_key.go	55.87% <0%> (-0.54%)	⬇️
models/repo_indexer.go	48.3% <0%> (ø)	⬆️

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[lunny]

@thehowl You should determine if the err is IsUserNotExist. Only that error you could ignore the log.

[thehowl]

Done.

[lunny]

@thehowl there is a function could do that. see https://github.com/thehowl/gitea/blob/f42e2d4771b8d158a7dbb8ec5ab34ffa4e7e1893/models/error.go#L84

[thehowl]

Refresh the change set ;). I remembered immediately after I committed

[lunny]

LGTM