Blockbase: hide no comments message (#4753)

* Hide no comments message.

* Comment why this line is needed.

blockbase/assets/ponyfill.css

@@ -652,6 +652,10 @@ p.has-drop-cap:not(:focus):first-letter {
 	margin-bottom: var(--wp--custom--gap--baseline);
 }
 
+.wp-block-post-comments .nocomments {
+	display: none;
+}
+
 .wp-block-post-template {
 	margin-top: 0;
 	margin-bottom: 0;

blockbase/sass/blocks/_post-comments.scss

@@ -157,4 +157,8 @@
 		margin-bottom: var(--wp--custom--gap--baseline);
 	}
 
+	// Needed until we have the option to hide this message via the block.
+	.nocomments {
+		display: none;
+	}
 }