Remove deprecated reference to writernames

[tomasMizera]

Luckily, it was read as an optional key so there is no need to keep the server compatible :)

[github-actions]

Pull Request Test Coverage Report for Build 12116425662

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 36 unchanged lines in 6 files lost coverage.
• Overall coverage decreased (-0.1%) to 60.442%

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Files with Coverage Reduction	New Missed Lines	%
input/app/main.cpp	2	32.65%
input/core/merginuserinfo.cpp	3	73.76%
input/app/notificationmodel.cpp	3	49.44%
input/core/merginprojectmetadata.cpp	4	88.51%
input/core/merginuserauth.cpp	9	75.95%
input/core/merginapi.cpp	15	78.73%

Totals
Change from base Build 12009384500:	-0.1%
Covered Lines:	7881
Relevant Lines:	13039

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💛 - Coveralls