規格1の存在チェックが正しく行われるよう修正

[pineray]

商品IDに紐づく商品規格の取得ルーチンにおいて、商品規格１の存在チェックが適切に行われていないので修正しました。

[codecov-commenter]

Codecov Report

Merging #530 (c3094a1) into master (4b76107) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master     #530   +/-   ##
=======================================
  Coverage   54.40%   54.40%           
=======================================
  Files          76       76           
  Lines        9039     9039           
=======================================
  Hits         4918     4918           
  Misses       4121     4121           

Flag	Coverage Δ
tests	54.40% <0.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
data/class/SC_Product.php	57.93% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4b76107...c3094a1. Read the comment docs.