HttpServer: Make read timeout configurable but disabled by default (#31575)

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

pkg/setting/setting.go

@@ -202,6 +202,7 @@ type Cfg struct {
 	RouterLogging    bool
 	Domain           string
 	CDNRootURL       *url.URL
+	ReadTimeout      time.Duration
 	EnableGzip       bool
 	EnforceDomain    bool
 
@@ -1368,6 +1369,8 @@ func (cfg *Cfg) readServerSettings(iniFile *ini.File) error {
 		}
 	}
 
+	cfg.ReadTimeout = server.Key("read_timeout").MustDuration(0)
+
 	return nil
 }