aurweb: increase burst size for smartgit endpoint

The burst size of 300 reportedly allows ~150 git operations. This might
not always be sufficient when installing a lot of packages from the AUR.

Specify a higher burst size to cover most legit use cases, even if this
makes us more susceptible to abuse.

roles/aurweb/templates/nginx.d.conf.j2

@@ -52,7 +52,7 @@ server {
     }
 
     location ~ "^/([a-z0-9][a-z0-9.+_-]*?)(\.git)?/(git-(receive|upload)-pack|HEAD|info/refs|objects/(info/(http-)?alternates|packs)|[0-9a-f]{2}/[0-9a-f]{38}|pack/pack-[0-9a-f]{40}\.(pack|idx))$" {
-	limit_req zone=aurwebgitlimit burst=300 nodelay;
+	limit_req zone=aurwebgitlimit burst=600 nodelay;
         include      uwsgi_params;
         uwsgi_pass   smartgit;
         uwsgi_modifier1 9;