Thousand separator separator in soft-credit amount fix

This fixes an issue where users try to edit softcredits that with values bigger than 1000. It creates a situation where api3 call is made with the amount value with thousand separator (which throws an error). That chunk of code should probably be reworked at some point, but the fix should work for now and should be merged (it was difficult to diagnose,as users didn't notice the why the problem was occurring).