Fix exception when trying to save default show settings. Fixes #4002

[medariox]

• PR is based on the DEVELOP branch
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There is still a bug I'd like to fix: saving new Default Settings without changing the quality preset causes the qualities to fall back to a different custom quality. Will be fixed in: #3818

[codecov-io]

Codecov Report

Merging #4027 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #4027   +/-   ##
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  Coverage    29.38%   29.38%           
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  Files          277      277           
  Lines        35492    35492           
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  Hits         10428    10428           
  Misses       25064    25064

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[fernandog]

@medariox does it fix when show only have allowed quality and the preferred quality wrongly sets SDTV in preferred?

[sharkykh]

@fernandog No, but it's already fixed and working in #3818 (for add show and edit show)