moving HttpUtilsTest to externalApi test task

[lbergelson]

• HttpUtilsTest is flakey because it connects to remote web servers.
  Moved it to the testExternalAPIs test task
• changed a broken link so that the tests pass again

Description

Please explain the changes you made here.
Explain the motivation for making this change. What existing problem does the pull request solve?

Checklist

• Code compiles correctly
• New tests covering changes and new functionality
• All tests passing
• Extended the README / documentation, if necessary
• Is not backward compatible (breaks binary or source compatibility)

[lbergelson]

fixes #1287

[codecov-io]

Codecov Report

Merging #1289 into master will increase coverage by 0.006%.
The diff coverage is n/a.

@@              Coverage Diff               @@
##             master     #1289       +/-   ##
==============================================
+ Coverage     67.49%   67.496%   +0.006%     
  Complexity     8150      8150               
==============================================
  Files           558       558               
  Lines         33365     33365               
  Branches       5608      5608               
==============================================
+ Hits          22518     22520        +2     
+ Misses         8658      8657        -1     
+ Partials       2189      2188        -1

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/htsjdk/samtools/util/HttpUtils.java	32.258% <0%> (-3.226%)	2% <0%> (-1%)
...samtools/util/AsyncBlockCompressedInputStream.java	76% <0%> (+4%)	13% <0%> (+1%)	⬆️

[yfarjoun]

👍

[lbergelson]

closes #1287