Fix invalid output of show-project; add unit test to verify

[osma]

No description provided.

[codecov]

Codecov Report

Merging #242 into master will increase coverage by 0.18%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #242      +/-   ##
==========================================
+ Coverage   99.03%   99.21%   +0.18%     
==========================================
  Files          48       48              
  Lines        2168     2177       +9     
==========================================
+ Hits         2147     2160      +13     
+ Misses         21       17       -4

Impacted Files	Coverage Δ
tests/test_cli.py	100% <100%> (ø)	⬆️
annif/cli.py	99.39% <100%> (+2.4%)	⬆️

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