Added fail safe

app/src/main/java/eu/faircode/email/Core.java

@@ -2178,6 +2178,7 @@ class Core {
             if (folder.tbc != null) {
                 try {
                     // Prefix folder with namespace
+                    try {
                         Folder[] ns = istore.getPersonalNamespaces();
                         if (ns != null && ns.length == 1) {
                             String n = ns[0].getFullName();
@@ -2190,6 +2191,9 @@ class Core {
                                 }
                             }
                         }
+                    } catch (MessagingException ex) {
+                        Log.w(ex);
+                    }
 
                     EntityLog.log(context, folder.name + " creating");
                     Folder ifolder = istore.getFolder(folder.name);