fixed compile error 

org.eclipse.emf.emfstore.client/src/org/eclipse/emf/emfstore/client/model/connectionmanager/SessionManager.java

diff --git a/org.eclipse.emf.emfstore.client/src/org/eclipse/emf/emfstore/client/model/connectionmanager/SessionManager.java b/org.eclipse.emf.emfstore.client/src/org/eclipse/emf/emfstore/client/model/connectionmanager/SessionManager.java
index eb88f3a..22489a3 100644
--- a/org.eclipse.emf.emfstore.client/src/org/eclipse/emf/emfstore/client/model/connectionmanager/SessionManager.java
+++ b/org.eclipse.emf.emfstore.client/src/org/eclipse/emf/emfstore/client/model/connectionmanager/SessionManager.java
@@ -27,7 +27,8 @@
 			throw new RuntimeException("Ouch.");

 		}

 		if (!isLoggedIn(usersession) || force) {

-			if (!usersession.getUsername().isEmpty() && usersession.getPassword() != null) {

+			if (!(usersession.getUsername() == null || usersession.getUsername().equals(""))

+				&& usersession.getPassword() != null) {

 				try {

 					// if login fails, let the session provider handle the rest

 					usersession.logIn();