Fix cron auto-import env vars and health check log spam for Firefly III Data Importer

- Source /etc/environment in cronupdate to load addon env vars (FIREFLY_III_URL, etc.)
- Persist cron-needed vars (JSON_CONFIGURATION_DIR, IMPORT_DIR_WHITELIST, etc.) to /etc/environment
- Fix inverted nginx map values that caused health check logs to spam while suppressing real requests

Co-authored-by: alexbelgium <44178713+alexbelgium@users.noreply.github.com>

fireflyiii_data_importer/Dockerfile

@@ -168,7 +168,7 @@ RUN \
     \
     # Handle Nginx configuration
     if [ -f /etc/nginx/nginx.conf ]; then \
-        awk '/http \{/{print; print "map $http_user_agent $dontlog {\n  default 0;\n  \"~*HealthCheck\" 1;\n}\naccess_log /var/log/nginx/access.log combined if=$dontlog;"; next}1' /etc/nginx/nginx.conf > /etc/nginx/nginx.conf.new && \
+        awk '/http \{/{print; print "map $http_user_agent $loggable {\n  default 1;\n  \"~*HealthCheck\" 0;\n}\naccess_log /var/log/nginx/access.log combined if=$loggable;"; next}1' /etc/nginx/nginx.conf > /etc/nginx/nginx.conf.new && \
         mv /etc/nginx/nginx.conf.new /etc/nginx/nginx.conf; \
     fi