only return a bluetooth module from factory if the rfkill feature is enabled.

include/factory.hpp

@@ -43,8 +43,10 @@
 #include "modules/custom.hpp"
 #include "modules/temperature.hpp"
 #if defined(__linux__)
+#  ifdef WANT_RFKILL
 #    include "modules/bluetooth.hpp"
 #  endif
+#endif
 
 namespace waybar {
 

src/factory.cpp

@@ -81,9 +81,11 @@ waybar::AModule* waybar::Factory::makeModule(const std::string& name) const {
       return new waybar::modules::Temperature(id, config_[name]);
     }
 #if defined(__linux__)
+#  ifdef WANT_RFKILL
     if (ref == "bluetooth") {
       return new waybar::modules::Bluetooth(id, config_[name]);
     }
+#  endif
 #endif
     if (ref.compare(0, 7, "custom/") == 0 && ref.size() > 7) {
       return new waybar::modules::Custom(ref.substr(7), id, config_[name]);