Redeclarating main conflict

[NViergever]

The following declaration conflicts with wxIMPLEMENT_APP, which already provides a declaration of main.
https://github.com/hampusborgos/rme/blob/7b303f3903e5a1c5431e750018d15e91394283f3/source/application.cpp#L644C1-L652C2