hide/ignore ssl_cert when on windows

x509.SystemCertPool is unavailable on windows, so any value is ignored
and the setting is hidden on the web UI.

api.go

@@ -1398,6 +1398,16 @@ func (app *appContext) GetConfig(gc *gin.Context) {
 			}
 		}
 	}
+	if PLATFORM == "windows" {
+		delete(resp.Sections["smtp"].Settings, "ssl_cert")
+		for i, v := range resp.Sections["smtp"].Order {
+			if v == "ssl_cert" {
+				sect := resp.Sections["smtp"]
+				sect.Order = append(sect.Order[:i], sect.Order[i+1:]...)
+				resp.Sections["smtp"] = sect
+			}
+		}
+	}
 	for sectName, section := range resp.Sections {
 		for settingName, setting := range section.Settings {
 			val := app.config.Section(sectName).Key(settingName)