mod_pgsql: err is now set correctly (dbh:last_error())

[ar45]

New function, void pgsql_handle_set_error_if_not_set(switch_pgsql_handle_t *handle, char **err) has been added to mod_pgsql module. This function is now called at several points where an error occurred but *err was not yet set.

[signalwire-ci[bot]]

Unit-tests failed: https://public-artifacts.signalwire.cloud/drone/signalwire/freeswitch/1670/artifacts.html

[signalwire-ci[bot]]

Scan-build found bugs: https://public-artifacts.signalwire.cloud/drone/signalwire/freeswitch/1670/index.html

[signalwire-ci[bot]]

Unit-tests failed: https://public-artifacts.signalwire.cloud/drone/signalwire/freeswitch/1672/artifacts.html