fix(xkeyboard): Only update indicators when used

Was causing a segfault if `format = <label-layout>`

src/modules/xkeyboard.cpp

@@ -130,6 +130,7 @@ namespace modules {
       m_layout->replace_token("%number%", to_string(m_keyboard->current()));
     }
 
+    if (m_formatter->has(TAG_LABEL_INDICATOR)) {
       m_indicators.clear();
 
       for (auto it : INDICATOR_TYPES) {
@@ -157,6 +158,7 @@ namespace modules {
         indicator->replace_token("%icon%", icon->get());
         m_indicators.emplace(it, move(indicator));
       }
+    }
 
     // Trigger redraw
     broadcast();