add margin to signup catpcha

static/css/style.css

@@ -40,6 +40,10 @@ div#captcha > div {
     text-align: center;
 }
 
+.signuppage .h-captcha {
+    margin-top: 1em;
+}
+
 /* Firefox fix */
 .formpage.pure-g {
     text-align: center;