fixed whitespace collapsing

lib/single-file/htmlmini.js

@@ -197,8 +197,7 @@ this.htmlmini = this.htmlmini || (() => {
 				noWhitespace = element && noWhitespaceCollapse(element);
 			}
 			if ((!element || noWhitespace) && textContent.length > 1) {
-				node.textContent = textContent.replace(/[ \t\f\r]+/g, getWhiteSpace(node));
-				node.textContent = textContent.replace(/[\n]+/g, getWhiteSpace(node));
+				node.textContent = textContent.replace(/[ \t\f\r]+/g, getWhiteSpace(node)).replace(/[\n]+/g, getWhiteSpace(node));
 			}
 		}
 	}