fix email with + when active (#17518)

Co-authored-by: zeripath <art27@cantab.net>

modules/templates/helper.go

@@ -498,6 +498,7 @@ func NewTextFuncMap() []texttmpl.FuncMap {
 			}
 			return sum
 		},
+		"QueryEscape": url.QueryEscape,
 	}}
 }