Fix warnings

[nanasess]

主に #1095 のテストで出力される warning の解消

[codecov]

Codecov Report

Attention: Patch coverage is 78.94737% with 4 lines in your changes missing coverage. Please review.

Project coverage is 50.60%. Comparing base (cd15650) to head (39133d1).
Report is 4 commits behind head on master.

Files with missing lines	Patch %	Lines
data/class/helper/SC_Helper_Delivery.php	0.00%	3 Missing ⚠️
data/class/helper/SC_Helper_FileManager.php	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1107      +/-   ##
==========================================
- Coverage   50.61%   50.60%   -0.01%     
==========================================
  Files          80       80              
  Lines       10256    10258       +2     
==========================================
  Hits         5191     5191              
- Misses       5065     5067       +2     

Flag	Coverage Δ
tests	50.60% <78.94%> (-0.01%)	⬇️

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