fix: Dont return toobusy errors for healthchecks.

If running with an orchestrator that restarts hedgedoc on failing
healthchecks, this causes it to enter a crashloop.

toobusy -> gets restarted -> everyone refreshes -> toobusy

Signed-off-by: Daniel Koschützki <daniel.koschuetzki@adfinis.com>

lib/web/middleware/tooBusy.js

@@ -8,6 +8,11 @@ const config = require('../../config')
 toobusy.maxLag(config.tooBusyLag)
 
 module.exports = function (req, res, next) {
+  // We dont want to return "toobusy" errors for healthchecks, as that
+  // will cause the process to be restarted
+  if (req.baseUrl === '/_health') {
+    next()
+  }
   if (toobusy()) {
     errors.errorServiceUnavailable(res)
   } else {