cli/tests: program_extend_program: Check for a specific error

[ilya-bobyr]

Problem

There are many errors that could be generated, creating a possibility for false positives. We actually observed it in this test.

Summary of Changes

Specify the expected error.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.1%. Comparing base (f291ca4) to head (26388c1).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##           master    #1165     +/-   ##
=========================================
- Coverage    82.1%    82.1%   -0.1%     
=========================================
  Files         886      886             
  Lines      236392   236392             
=========================================
- Hits       194274   194224     -50     
- Misses      42118    42168     +50     

[CriesofCarrots]

Thanks, it will be great to check the specific error. Just one question