Set architecture=esp8266 for bundled SD and Ethernet libraries (esp8266#4035)

Fixes esp8266#3868.

Author: igrr

libraries/Ethernet/library.properties

@@ -6,4 +6,4 @@ sentence=Enables network connection (local and Internet) using the Arduino Ether
 paragraph=With this library you can use the Arduino Ethernet (shield or board) to connect to Internet. The library provides both Client and server functionalities. The library permits you to connect to a local network also with DHCP and to resolve DNS.
 category=Communication
 url=http://www.arduino.cc/en/Reference/Ethernet
-architectures=*
+architectures=esp8266

libraries/SD/library.properties

@@ -6,4 +6,4 @@ sentence=Enables reading and writing on SD cards. For all Arduino boards.
 paragraph=Once an SD memory card is connected to the SPI interfare of the Arduino board you are enabled to create files and read/write on them. You can also move through directories on the SD card.
 category=Data Storage
 url=http://www.arduino.cc/en/Reference/SD
-architectures=*
+architectures=esp8266