[server] print backend exception if we fail to execute an sql script
It's more useful to see
could not open extension control file "/usr/share/postgresql/9.4/extension/postgis.control": No such file or directory
rather than merely
-> ERROR, skipping /usr/share/cubicweb/cubes/postgis/schema/_ext.postgres.sql
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception