sources: follow SOURCES_URL redirects; remove noproxy requirement

The curl --no-proxy hint is not needed anymore, since Clear Linux OS has
an autoproxy, and curl will honor proxy environment variables.

Also, pass -L to curl to follow redirects, similarly to other curl calls
in this makefile.

Signed-off-by: Patrick McCarty <patrick.mccarty@intel.com>

Makefile.common

@@ -221,7 +221,7 @@ ifneq ($(strip $(SOURCES_URL)),)
 		    *://*) n="$$u" ;; \
 		    *)     n="$(SOURCES_URL)/$$u" ;; \
 		esac; \
-		curl --fail --noproxy "*" "$$n" -o `basename "$$n"`; \
+		curl --fail -L "$$n" -o `basename "$$n"`; \
 	done < upstream
 else
 	@tmp=$$(mktemp -d -p "."); \