Null guard for dtTracer in httpurlconnection MetricState

[obenkenobi]

Overview

Continuation of the previous PR to replace TracedMethod instances with weak references in HttpUrlConnection. This just adds an additional null guard.

Related Github Issue

https://github.com/newrelic/newrelic-java-agent/issues/2048

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 70.70%. Comparing base (eb28f6c) to head (4291fea). Report is 61 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2086      +/-   ##
============================================
+ Coverage     70.58%   70.70%   +0.12%     
- Complexity     9878     9981     +103     
============================================
  Files           829      841      +12     
  Lines         39960    40289     +329     
  Branches       6081     6107      +26     
============================================
+ Hits          28205    28487     +282     
- Misses         9022     9055      +33     
- Partials       2733     2747      +14     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.