improve error message, make link clickable

[timotheecour]

before PR: error message contains a dot, which prevents making the link clickable in logs (eg github action logs)

after PR: I remove the dot so the link becomes clickable.

example: https://github.com/nim-lang/Nim/runs/2063531199

 PASS: norm c                                                       ( 6.54 sec)
  PASS: npeg c                                                       (17.42 sec)
  FAIL: numericalnim c
  Test "numericalnim" in category "nimble-packages-2"
  Failure: reInstallFailed
  nimble install --depsOnly -y
    Verifying dependencies for [email protected]
   Installing arraymancer@>= 0.5.0
  Downloading mratsim/Arraymancer using git
    Verifying dependencies for [email protected]
        Info: Dependency on nimblas@>= 0.2.2 already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on nimlapack@>= 0.1.1 already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on nimcuda@>= 0.1.4 already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on nimcl@>= 0.1.3 already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on opencl@>= 1.0 already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on clblast@any version already satisfied
    Verifying dependencies for [email protected]
        Info: Dependency on opencl@any version already satisfied
    Verifying dependencies for [email protected]
   Installing stb_image@any version
  Downloading gitlab.com/define-private-public/stb_image-Nim.git using git
  download.nim(93)         getTagsListRemote
  Error: unhandled exception: Unable to query remote tags for gitlab.com/define-private-public/stb_image-Nim.git. Git returned: fatal: unable to access 'gitlab.com/define-private-public/stb_image-Nim.git': The requested URL returned error: 502
   [OSError]
  
  PASS: optionsutils c                                               (10.26 sec)