[FIX] Handled edge cases exception for email providers that does not support script inclusion

[josaphatim]

Below is the error message returned by postale.io when including a script

NO {151}
main_script: line 3: error: failed to include script 'blocked_senders': no more than 0 includes allowed.
main_script: error: code generation failed.

When client manager read the first line it is the size expression error but the right error comes on the line after