Change Error message for too small vote_weight

[Elblinator]

Current behaviour:
If the vote_weight is too small ( < 0.000001) then the following Error is thrown:

vote_weight must be bigger than or equal to 0.000001.

Wanted behaviour:
If a user with vote_weight <= 0 is saved then the thrown error should be:

vote_weight must be great than 0

If a user with vote_weight >0 but <0.000001 is saved then the following error should be thrown:

vote_weight must be greater than or equal to 0.000001.

[jsangmeister]

If a user with vote_weight >0 but <0.000001 is saved

This is not possible: The vote weight is limited to 6 decimal places, so 0.000001 is the lowest possible number (that's why we chose it as the minimum).

[jsangmeister]

as discussed, will be solved in the client as the backend always expects a six-digit number

[Elblinator]

Okay, then the client needs to prevent this error from happening and not the backend
The backend issue will be closed