Warn backend users if they try to double book a provider from the calendar page

[rabongithub]

Hello,

There needs some checking at the backend (when editing or saving new appointment) that multiple insert is not possible for the same provider of similar/overlapping date and time.

[alextselegidis]

Hello!

In general this is by design so, as the app should allow for any custom scheduling set up in the backend.

Being said, I wanted to add a warning so that users at least get informed that there is another conflicting appointment.

Alex Tselegidis, Easy!Appointments Creator Need a customization? Get a free quote!

[rabongithub]

Hello! Yes, actually that is even better, more flexibility at the backend but warn the users about double book.