Change server-proxy-uri 2 openapi-server-proxy-uri

The server-proxy-uri config option mislead into thinking it was a
web server global setting when it's only related to OpenAPI.

docker/Dockerfile

@@ -31,7 +31,7 @@ ENV PGRST_DB_URI= \
     PGRST_DB_EXTRA_SEARCH_PATH=public \
     PGRST_SERVER_HOST=*4 \
     PGRST_SERVER_PORT=3000 \
-    PGRST_SERVER_PROXY_URI= \
+    PGRST_OPENAPI_SERVER_PROXY_URI= \
     PGRST_JWT_SECRET= \
     PGRST_SECRET_IS_BASE64=false \
     PGRST_JWT_AUD= \

docker/postgrest.conf

@@ -7,7 +7,7 @@ db-extra-search-path = "$(PGRST_DB_EXTRA_SEARCH_PATH)"
 server-host = "$(PGRST_SERVER_HOST)"
 server-port = "$(PGRST_SERVER_PORT)"
 
-server-proxy-uri = "$(PGRST_SERVER_PROXY_URI)"
+openapi-server-proxy-uri = "$(PGRST_OPENAPI_SERVER_PROXY_URI)"
 jwt-secret = "$(PGRST_JWT_SECRET)"
 secret-is-base64 = "$(PGRST_SECRET_IS_BASE64)"
 jwt-aud = "$(PGRST_JWT_AUD)"