Compile fix on linux

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@2005 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_nJoy_SDL/Src/GUI/ConfigJoypad.cpp

@@ -226,7 +226,7 @@ wxString ConfigBox::GetButtonText(int id)
 		case IDB_BUTTONSTART: return m_JoyButtonStart[controller]->GetValue();
 
 		case IDB_BUTTONHALFPRESS: return m_JoyButtonHalfpress[controller]->GetValue();
-		default: return wxString("");
+		default: return wxString();
 	}
 }