Explicitly decide whether to use TLS in mailer's configuration

[adelowo]

Fixes #4820

[codecov-io]

Codecov Report

Merging #5024 into master will increase coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #5024      +/-   ##
==========================================
+ Coverage   37.45%   37.45%   +<.01%     
==========================================
  Files         312      312              
  Lines       46510    46510              
==========================================
+ Hits        17419    17422       +3     
+ Misses      26599    26597       -2     
+ Partials     2492     2491       -1

Impacted Files	Coverage Δ
modules/mailer/mailer.go	3.95% <0%> (+0.02%)	⬆️
modules/setting/setting.go	48.06% <0%> (-0.07%)	⬇️
modules/process/manager.go	81.15% <0%> (+4.34%)	⬆️

---

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 ce9a517...a393bd9. Read the comment docs.

[lafriks]

It should probably use default depending on port set to not break compatibility

[adelowo]

Sorry for not updating this on time. I have been a little busy this past 2 weeks.

I would be updating my other PRs before the start of next week

[techknowlogick]

@adelowo no worries. We appreciate the time you are able to give.