[stable-1] Add IF EXISTS clause to DROP USER statement

[Andersson007]

SUMMARY

Backport of #307

ISSUE TYPE

• Bugfix Pull Request

[codecov]

Codecov Report

Merging #309 (61862ac) into stable-1 (96a255c) will decrease coverage by 0.06%.
The diff coverage is 50.00%.

@@             Coverage Diff              @@
##           stable-1     #309      +/-   ##
============================================
- Coverage     75.15%   75.09%   -0.07%     
============================================
  Files            22       22              
  Lines          1900     1903       +3     
  Branches        466      466              
============================================
+ Hits           1428     1429       +1     
- Misses          323      325       +2     
  Partials        149      149              

Impacted Files	Coverage Δ
plugins/modules/mysql_user.py	82.29% <50.00%> (-0.29%)	⬇️

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