Add repository setting to enable/disable health checks

[aswild]

New Feature:

• Repository struct field for IsFsckEnabled (default true of course)
• Admin Settings section on repo options page, accessible only by
  admin users

Possible Enhancements:

• There's no way to force running health checks on all repos
  regardless of their IsFsckEnabled setting. This would be useful if
  there were an admin API or dashboard button to run fsck immediately.

Signed-off-by: Allen Wild allenwild93@gmail.com

[codecov-io]

Codecov Report

Merging #3607 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #3607      +/-   ##
==========================================
- Coverage   35.79%   35.77%   -0.02%     
==========================================
  Files         288      288              
  Lines       41581    41519      -62     
==========================================
- Hits        14882    14854      -28     
+ Misses      24503    24477      -26     
+ Partials     2196     2188       -8

Impacted Files	Coverage Δ
models/migrations/migrations.go	2.58% <ø> (ø)	⬆️
modules/auth/repo_form.go	33.76% <ø> (ø)	⬆️
models/repo.go	42.67% <0%> (ø)	⬆️
routers/repo/setting.go	7.12% <0%> (-0.23%)	⬇️
modules/process/manager.go	76.81% <0%> (-4.35%)	⬇️
routers/repo/setting_protected_branch.go	44.44% <0%> (-0.56%)	⬇️
models/migrations/v59.go	0% <0%> (ø)	⬆️
models/repo_indexer.go	48.3% <0%> (ø)	⬆️
... and 3 more

---

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[aswild]

Rationale:

• Issue Add an option to omit health checks for some repositories #1712 requests an option to disable health checks, but I made an option to enable them to avoid confusing inverse logic
• By default, health checks are enabled for all repos, including mirrors
  • This keeps behavior consistent with older version
  • Git fsck verifies the integrity of the files on disk, just because a repo is a mirror doesn't mean it couldn't become corrupted
• I added the new admin settings as a section on the Settings->Options tab rather than adding a whole new tab just for one checkbox

Testing:

• The migration works on sqlite3, I don't have a MySQL or PostgreSQL setup to test on
• I used BurpSuite to alter a POST request to try to set the admin option as a non-admin user. It returned 403 as expected

[lafriks]

Why it must be only server admin option?

[aswild]

Enabling, configuring, running, and viewing the results of fsck are things that only admins have access to (via app.ini and the admin panel), so it seemed to make sense that normal users don't need this setting exposed.

The main reason to disable fsck is for large repos which take too long to check, but only an admin would know when that's the case. If users could toggle that setting, they a) wouldn't be able to see any actual result and b) might annoy admins who intentionally it set a particular way.

If this is the wrong view, I can remove the admin-only restriction.

[lafriks]

@aswild that makes sense :)