use line-height from probe

Author: CGastrell

projects/packages/forms/src/blocks/input-phone/editor.scss

@@ -8,7 +8,7 @@
 		border-radius: var(--jetpack--contact-form--border-radius);
 		border-width: var(--jetpack--contact-form--border-size);
 		font-size: var(--jetpack--contact-form--font-size);
-		line-height: 2; // matches default input line-height
+		line-height: var(--jetpack--contact-form--line-height);
 		// defaulting to white, it's gutenberg's default background for inputs
 		background-color: var(--jetpack--contact-form--input-background, #fff);