fix: skip phinx migration when env file is absent

Without /etc/csas-authorize/csas-authorize.env the DB_CONNECTION config
is empty, causing phinx to fail with "Unimplemented Database type".
Only run migrations when the env file exists (i.e. database is configured).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Vitexus

debian/csas-authorize.postinst

@@ -6,7 +6,7 @@ set -e
 . /usr/share/debconf/confmodule
 
 
-if [ -f /usr/share/dbconfig-common/dpkg/postinst ]; then
+if [ -f /usr/share/dbconfig-common/dpkg/postinst ] && [ -f /etc/csas-authorize/csas-authorize.env ]; then
 
     phinx migrate -c /usr/lib/csas-authorize/phinx-adapter.php