hw: fix 512kb build with recent Core

ref. https://travis-ci.com/github/mcspr/espurna-nightly-builder/jobs/378203413#L698

> +env ESPURNA_FLAGS=-DGENERIC_ESP01_512KB ESPURNA_RELEASE_NAME=generic-esp01-512kb ESPURNA_BUILD_SINGLE_SOURCE=1 pio run -e esp8266-512k-base -s -t release
> /home/travis/.platformio/packages/toolchain-xtensa/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/bin/ld: .pio/build/esp8266-512k-base/firmware.elf section `.irom0.text' will not fit in region `irom0_0_seg'

Remove ~90Kb from the build.

code/espurna/config/hardware.h

@@ -1769,6 +1769,9 @@
     #define OTA_ARDUINOOTA_SUPPORT   0
     #define OTA_CLIENT               OTA_CLIENT_NONE
 
+    // Web UI blob & MDNS are pretty large
+    #define WEB_EMBEDDED             0
+    #define MDNS_SERVER_SUPPORT      0
 
 // -----------------------------------------------------------------------------
 // ESPLive