[Network] set_custom_vec2 is not synced if Vector2.x or y is 0

[fairhat]

Noticed a bug where a custom vec2 action is not synced if x or y is 0

the vector2 is set on the client but either not sent to the server or the server is decoding it incorrectly.

Steps to reproduce:

• Set a custom Vector2 action
• Change the x value of the Vector2 every physics step but keep y at 0
• Input will be out of sync