fix(filebrowser-q): migrate legacy Quantum config

filebrowser-q/files/filebrowser.init

@@ -46,6 +46,21 @@ userDefaults:
     locale: "zhCN"
 EOF
     else
+        # Migrate config files generated by older package versions.
+        if grep -q '^  database: "' "$CONF_PATH"; then
+            sed -i \
+                -e "s/^server:$/http:\\n  port: $listen_port\\nserver:/" \
+                -e "/^  port:/d" \
+                -e 's,^  database: "\(.*\)",  database:\n    path: "\1",' \
+                -e '/^auth:$/a\
+  methods:\
+    password:\
+      enabled: true' \
+                -e 's/^  adminUsername:/      adminUsername:/' \
+                -e 's/^  adminPassword:/      adminPassword:/' \
+                "$CONF_PATH"
+        fi
+
         grep -q " name:" "$CONF_PATH" || sed -i "s,.*- path:.*,&\n      name: \"\"," "$CONF_PATH"
         sed -e "s/^  port:.*/  port: $listen_port/" \
             -e "s, - path:.*, - path: \"$root_path\"," \