compiler: Hotfix unevaluation.Pow(1, ...)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 86.67%. Comparing base (ccfb823) to head (774606b).

Files	Patch %	Lines
devito/symbolics/unevaluation.py	50.00%	1 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2321 +/- ## ========================================== - Coverage 86.67% 86.67% -0.01% ========================================== Files 229 229 Lines 43150 43153 +3 Branches 8001 8002 +1 ========================================== + Hits 37401 37402 +1 - Misses 5053 5054 +1 - Partials 696 697 +1 ```

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