message: Fix error message in rtc_base/system/arch.h
  No-Try: True
  Cr-Commit-Position: refs/heads/master@{#28199}
diff: #define WEBRTC_ARCH_32_BITS
  #define WEBRTC_ARCH_LITTLE_ENDIAN
  #else
  -#error Please add support for your architecture in typedefs.h
  +#error Please add support for your architecture in rtc_base/system/arch.h
  #endif
  #if !(defined(WEBRTC_ARCH_LITTLE_ENDIAN) ^ defined(WEBRTC_ARCH_BIG_ENDIAN))
  