Prevent crash when reading cursor in DirectoryHelper.

The cause of the crash is very unclear. Our best guess at present is
that the cursor is unable to fit a single row within the 2mb allocation
window, and therefore can't read anything. In this case, the best we can
do is catch the exception and develop some future fallback. Logging the
exception will also mean that maybe we'll be able to get the actual
exception message.

app/src/main/java/org/thoughtcrime/securesms/contacts/sync/DirectoryHelper.java

@@ -378,7 +378,8 @@ public class DirectoryHelper {
 
           contactHolder.commit(handle);
         }
-
+      } catch (IllegalStateException e) {
+        Log.w(TAG, "Hit an issue with the cursor while reading!", e);
       } finally {
         handle.finish();
       }