[2.0.x] Fix compile Error Anet (#9509)

platformio.ini

@@ -84,6 +84,18 @@ lib_deps     = ${common.lib_deps}
 src_filter   = ${common.default_src_filter}
 
 #
+# Anet 1.0 (Optiboot bootloader)
+#
+[env:anet10_optiboot]
+platform     = atmelavr
+framework    = arduino
+board        = sanguino_atmega1284p
+build_flags  = ${common.build_flags}
+upload_speed = 115200
+lib_deps     = ${common.lib_deps}
+src_filter   = ${common.default_src_filter}
+
+#
 # Due (Atmel SAM3X8E ARM Cortex-M3)
 #
 #  - RAMPS4DUE