Downgrade flask-appbuilder dependency

[villebro]

It seems that flask-appbuilder-1.11 is more strict about sqlalchemy exceptions than 1.10. Should fix #5088

[codecov-io]

Codecov Report

Merging #5127 into 0.25 will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             0.25    #5127   +/-   ##
=======================================
  Coverage   77.04%   77.04%           
=======================================
  Files          44       44           
  Lines        8562     8562           
=======================================
  Hits         6597     6597           
  Misses       1965     1965

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[xrmx]

See #5122

[villebro]

Thanks, hadn't noticed that, would have saved me some effort finding the root cause of #5088. This PR is against the 0.25 branch, which I think we need to stabilize asap, but for the long term plan (master branch) it would probably be ideal to to stay on current versions of dependencies.