GUACAMOLE-723: Persist client panel state across navigation.

guacamole/src/main/webapp/app/client/styles/other-connections.css

@@ -26,6 +26,7 @@
 
 #other-connections .client-panel {
 
+    display: none;
     position: absolute;
     right: 0;
     bottom: 0;
@@ -38,6 +39,10 @@
 
 }
 
+#other-connections .client-panel.has-clients {
+    display: block;
+}
+
 #other-connections .client-panel.hidden {
     max-width: 16px;
 }