Fixes https://github.com/GeoNode/geonode-project/issues/562 Backup.sh procedure is just able to run once

[kikislater]

Fixes GeoNode/geonode-project#562 @caocuongngo

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.59%. Comparing base (03a6578) to head (61a5e67).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #13215      +/-   ##
==========================================
- Coverage   72.59%   72.59%   -0.01%     
==========================================
  Files         916      916              
  Lines       52636    52636              
  Branches     6058     6058              
==========================================
- Hits        38212    38210       -2     
- Misses      12857    12860       +3     
+ Partials     1567     1566       -1     

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