Fix v2 cli flag being incorrectly applied

[mky2]

This fixes a problem with the watch command when using v2 cli with a symlink named nextonic .

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.

Project coverage is 47.03%. Comparing base (04659a4) to head (6d5af15). Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
src/bin/tectonic/v2cli/commands/watch.rs	0.00%	10 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1270      +/-   ##
==========================================
- Coverage   47.03%   47.03%   -0.01%     
==========================================
  Files         184      184              
  Lines       66302    66309       +7     
  Branches    66302    66309       +7     
==========================================
  Hits        31188    31188              
- Misses      35114    35121       +7     

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[CraftSpider]

Looks good! Thanks for the patience with the 2-month review lag.

[CraftSpider]

/AzurePipelines run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[CraftSpider]

/AzurePipelines run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).