avoid margins on buttons

Author: CGastrell

projects/packages/forms/src/blocks/contact-form/editor.scss

@@ -67,6 +67,7 @@
 				min-height: var(--jetpack--contact-form--input-height, auto);
 				align-self: flex-end;
 				line-height: 1;
+				margin-block: 0;
 
 				.wp-block-button__link {
 					min-height: var(--jetpack--contact-form--input-height, auto);