sanitize external_url, remove trailing slashes

internal/config/web.go

@@ -1,5 +1,7 @@
 package config
 
+import "strings"
+
 // WebConfig contains the configuration for the web server.
 type WebConfig struct {
 	// RequestLogging enables logging of all HTTP requests.
@@ -26,3 +28,7 @@ type WebConfig struct {
 	// KeyFile is the path to the TLS certificate key file.
 	KeyFile string `yaml:"key_file"`
 }
+
+func (c *WebConfig) Sanitize() {
+	c.ExternalUrl = strings.TrimRight(c.ExternalUrl, "/")
+}