Fix name and a crash for guest user

app/src/main/java/in/ac/iitb/gymkhana/iitbapp/MainActivity.java

@@ -264,7 +264,7 @@ public class MainActivity extends AppCompatActivity implements NavigationView.On
         }
         bundle.putString(Constants.SESSION_ID, session.pref.getString(Constants.SESSION_ID, "Error"));
         if (fragment instanceof MessMenuFragment)
-            bundle.putString(Constants.USER_HOSTEL, currentUser.getHostel());
+            bundle.putString(Constants.USER_HOSTEL, session.isLoggedIn() ? currentUser.getHostel() : "1");
         if (fragment instanceof SettingsFragment && session.isLoggedIn())
             bundle.putString(Constants.USER_ID, currentUser.getUserID());
         fragment.setArguments(bundle);

app/src/main/res/layout/nav_header_main.xml

@@ -17,20 +17,20 @@
         android:layout_width="64dp"
         android:layout_height="64dp"
         android:paddingTop="@dimen/nav_header_vertical_spacing"
-        app:srcCompat="@mipmap/ic_launcher_round" />
+        android:src="@drawable/user_placeholder" />
 
     <TextView
         android:id="@+id/user_name_nav_header"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:paddingTop="@dimen/nav_header_vertical_spacing"
-        android:text="Android Studio"
+        android:text="Guest"
         android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
 
     <TextView
         android:id="@+id/user_rollno_nav_header"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="android.studio@android.com" />
+        android:text="IITB User" />
 
 </LinearLayout>