Update PortableCharger.java

[nextrodium]

Short Description

Fixed energy dupe.

Before:
With 3+ portable chargers, you can dupethe energy between them
Now:
if the item is an instance of PortableCharger, it will not be recharged

(You can place a portable charger in the charger GUI just by using the numbers on the keyboard with the charger in the hotbar)

Additions/Changes/Removals

changed 2 consecutive if statements to if else if statements

Video Proof

Before: https://streamable.com/f3eps0
After: https://streamable.com/sehwy8

Checklist

• I have fully tested the proposed changes and promise that they will not break everything into chaos.
• I have also tested the proposed changes in combination with base Slimefun and made sure nothing breaks/unexpected happens.
• I followed the existing code standards and didn't mess up the formatting.

[nextrodium]

Not a big deal for many people, but I'm making my own addon (even though SlimeFun is no longer in development) and this “dupe” would cause me some problems... sorry to bother you