Fix dev:oidc npm script

* generate public/client-config.js at foreman startup
* remove nginx's special handling for client-config.js

Closes getodk#1034

.gitignore

@@ -27,3 +27,4 @@ npm-debug.log*
 !/.nginx/.gitkeep
 
 /.eslintcache
+/public/client-config.json

Procfile

@@ -1,2 +1,2 @@
-vue: vue-cli-service build --mode development --watch
-nginx: nginx -c "$PWD/main.nginx.conf" -p "$PWD" -e stderr
+vue: echo "{\"oidcEnabled\":${VUE_APP_OIDC_ENABLED-false}}" >./public/client-config.json && vue-cli-service build --mode development --watch
+nginx: docker run --rm --network=host -v $PWD/nginx-conf:/etc/nginx/:ro -v $PWD/dist:/odk-central-frontend/dist nginx

main.nginx.conf

@@ -94,11 +94,6 @@ http {
       proxy_set_header X-Forwarded-Proto https;
     }
 
-    location = /client-config.json {
-      include ./common-headers.nginx.conf;
-      return 200 "{}";
-    }
-
     location / {
       root ./dist;