allow overriding API URLs for Epirus web UI

Signed-off-by: Jakub Sokołowski <jakub@status.im>

docker-compose.yml

@@ -208,8 +208,8 @@ services:
     ports:
       - 0.0.0.0:3000:3000
     environment:
-      - API_URL=http://localhost:8090
-      - WS_API_URL=ws://localhost:8090
+      - API_URL=${EPIRUS_WEB_API_URL:-http://localhost:8090}
+      - WS_API_URL=${EPIRUS_WEB_WS_API_URL:-ws://localhost:8090}
       - DISPLAY_NETWORK_TAB=disabled
     depends_on:
       - api