Remove check for negative length

[cristaloleg]

Found by go-critic sloppyLen checker

Log:

modules/user/user_test.go:21:5 sloppyLen len(user) <= 0 can be len(user) == 0
models/issue_label.go:137:5 sloppyLen len(labelName) <= 0 can be len(labelName) == 0
models/org.go:680:5 sloppyLen len(repoIDs) <= 0 can be len(repoIDs) == 0
models/org.go:708:5 sloppyLen len(repoIDs) <= 0 can be len(repoIDs) == 0
models/ssh_key.go:379:5 sloppyLen len(key.Fingerprint) <= 0 can be len(key.Fingerprint) == 0
routers/user/home.go:216:5 sloppyLen len(userRepoIDs) <= 0 can be len(userRepoIDs) == 0
routers/api/v1/api.go:83:6 sloppyLen len(sudo) <= 0 can be len(sudo) == 0
modules/auth/auth.go:39:6 sloppyLen len(tokenSHA) <= 0 can be len(tokenSHA) == 0

[codecov-io]

Codecov Report

Merging #5120 into master will decrease coverage by <.01%.
The diff coverage is 57.14%.

@@            Coverage Diff            @@
##           master   #5120      +/-   ##
=========================================
- Coverage    37.4%   37.4%   -0.01%     
=========================================
  Files         308     308              
  Lines       45612   45612              
=========================================
- Hits        17062   17060       -2     
- Misses      26093   26095       +2     
  Partials     2457    2457

Impacted Files	Coverage Δ
routers/user/home.go	41.64% <0%> (ø)	⬆️
models/ssh_key.go	38.96% <0%> (ø)	⬆️
routers/api/v1/api.go	75.37% <100%> (ø)	⬆️
models/issue_label.go	59.51% <100%> (ø)	⬆️
modules/auth/auth.go	55.24% <100%> (ø)	⬆️
models/org.go	68.6% <50%> (ø)	⬆️
models/repo_list.go	62.2% <0%> (-1.17%)	⬇️

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[lunny]

Is that really usable?

[cristaloleg]

1. We're checking 100% non-negative value for a negative value, so it's false all the time. It's redundant and brings a noise in the code.
2. Also grepping code for == 0 (to quickly find checks for an empty string/slice/map) will not be found, we need explicitly grep <= 0, this brings unneeded complexity for new contributors 😉