AMBARI-6751. HostNames and Slaves broken in two lines on Assign Slaves step.(xiwang)

ambari-web/app/styles/application.less

@@ -802,6 +802,9 @@ h1 {
       max-height: 440px;
       position: relative;
       #component_assign_table {
+        tbody td {
+          white-space: nowrap;
+        }
         .trim_hostname {
           max-width: 180px;
           float:left;