fixed opening inventory not stopping use of enderic railgun

[Fiverka21]

Description

I fixed opening inventory not stopping the use of enderic railgun, an issue found here: #838
Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Fixes # (issue)
I fixed this by a small change in the code

How Has This Been Tested?

i tested this by reproducing the steps described in the bug report, it went away after applying the fix
Please describe the tests that you ran to verify your changes. All changes have to be tested ingame on both loaders, and if any client-side code is involved, also on
a dedicated server to avoid any issues there.

• [yes ] Feature has been tested ingame on both neoforge and fabric.
• Optional additional testing details

Checklist:

• My code uses the 'var' keyword where applicable.
• I have commented my code, particularly in hard-to-understand areas
  doesnt apply here since its not a complicated fix

[Rearth]

Hi, thanks for the simple fix.