Skip check for building care, patch by Patrick Lauer <patrick AT gentoo.org>

--- src/GNUmakefile   2014-02-25 16:42:04.336863622 +0800
+++ src/GNUmakefile.new       2014-02-25 16:42:26.063050467 +0800
@@ -54,15 +54,6 @@
 all: proot
 
 ######################################################################
-# Sanity checks
-
-ifneq (,$(findstring care,$(MAKECMDGOALS)))
-ifneq ($(CARE_BUILD_ENV),ok)
-$(error care is supposed to be built with: http://build.reproducible.io)
-endif
-endif
-
-######################################################################
 # Beautified output
 
 quiet_GEN = @echo "  GEN       $@"; $(GEN)