Set LC_ALL=C in build config (#43)

It's most likely the case (and SHOULD be the case) that C is the same
locale as C.UTF-8. The only exception might be Python's gonzo unicode
handling which whines when unicode is used without authorization, but
that shouldn't be an issue since we don't need Python to build.

build/definitions.mk

@@ -43,7 +43,7 @@
 #     TARGET_ARCH  microarchitecture flags (e.g. -march=native)
 
 V ?= 1
-LC_ALL = C.UTF-8
+LC_ALL = C
 SOURCE_DATE_EPOCH = 0
 
 DD ?= /bin/dd