fix: Prevent possible nil pointer dereference in project API

[jannfis]

Fixes #5249

There already have been a couple of similar issues in other APIs (#5130, #5128), and I think there might be a couple more.

Signed-off-by: jannfis jann@mistrust.net

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[codecov-io]

Codecov Report

Merging #5263 (b4fefd1) into master (e26ad30) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #5263      +/-   ##
==========================================
- Coverage   40.90%   40.89%   -0.01%     
==========================================
  Files         136      136              
  Lines       18419    18423       +4     
==========================================
  Hits         7534     7534              
- Misses       9810     9813       +3     
- Partials     1075     1076       +1     

Impacted Files	Coverage Δ
server/project/project.go	55.46% <0.00%> (-0.92%)	⬇️

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[alexmt]

LGTM