add NO_GLOBAL_UPDATE global buold flag

would save 180 bytes on Updater class instance
espressif/arduino-esp32#8500

platformio.ini

@@ -20,16 +20,14 @@ build_unflags =
 build_flags =
     -std=gnu++17
     ;!python git_rev_macro.py
-    -DFZ_WITH_ASYNCSRV
-    -DFZ_NOHTTPCLIENT
+    -DFZ_WITH_ASYNCSRV -DFZ_NOHTTPCLIENT
+    -DNO_GLOBAL_UPDATE
     ; -DEMBUI_IFACE_DYN_JSON_SIZE=2048
     ; -DEMBUI_SMALL_JSON_SIZE=768
     ; -DEMBUI_CFGSIZE=3072
     ;-DEMBUI_TZONE=TZ_Etc_GMT
     -DEMBUI_IDPREFIX='"FireLamp"'
-    -DEMBUI_USE_EXTERNAL_WS_BUFFER=4096
     -DEMBUI_USE_SSDP
-    ;-DEMBUI_USE_UDP
     -DEMBUI_MQTT
     -DEMBUI_SSDP_NAME="FireLamp"
     ;-DEMBUI_SSDP_URLMODEL="https:__I(/)__I(/)github.com/DmytroKorniienko/FireLamp_EmbUI"