Fix db selection when nav tree is disabled

[MauricioFauth]

$cfg['ShowDatabasesNavigationAsTree'] = false;

After selecting a database when the navigation tree is disabled, it is not possible to select another database.

[codecov]

Codecov Report

Merging #17198 (d7ced91) into QA_5_1 (90d6324) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##             QA_5_1   #17198   +/-   ##
=========================================
  Coverage     57.78%   57.78%           
  Complexity    15324    15324           
=========================================
  Files           471      471           
  Lines         62125    62127    +2     
=========================================
+ Hits          35897    35899    +2     
  Misses        26228    26228           

Flag	Coverage Δ
arch-7-amd64	61.14% <100.00%> (+<0.01%)	⬆️
arch-7-arm32v6	61.02% <100.00%> (+<0.01%)	⬆️
arch-7-arm32v7	61.02% <100.00%> (+<0.01%)	⬆️
arch-7-arm64v8	61.14% <100.00%> (+<0.01%)	⬆️
arch-7-i386	61.02% <100.00%> (+<0.01%)	⬆️
arch-7-ppc64le	61.14% <100.00%> (+<0.01%)	⬆️
arch-7-s390x	60.99% <100.00%> (+<0.01%)	⬆️
dbase-extension	57.47% <100.00%> (+<0.01%)	⬆️
recode-extension	57.42% <100.00%> (+<0.01%)	⬆️
unit-7.1-ubuntu-latest	57.42% <100.00%> (+<0.01%)	⬆️
unit-7.2-ubuntu-latest	57.60% <100.00%> (+<0.01%)	⬆️
unit-7.3-ubuntu-latest	61.16% <100.00%> (+<0.01%)	⬆️
unit-7.4-ubuntu-latest	61.16% <100.00%> (+<0.01%)	⬆️
unit-8.0-ubuntu-latest	61.21% <100.00%> (+<0.01%)	⬆️
unit-8.1-ubuntu-latest	61.10% <100.00%> (+<0.01%)	⬆️

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Impacted Files	Coverage Δ
libraries/classes/Navigation/NavigationTree.php	63.19% <100.00%> (+0.08%)	⬆️

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