Used spaces instead of tabs in Makefile.cfg

src/Makefile.cfg

@@ -61,10 +61,10 @@ ifeq   (,$(filter GCC% CLEANONLY,$(.VARIABLES)))
 
   # If this version is not in the list, default to the latest supported
   ifeq (,$(filter $(v),$(SUPPORTED_GCC_VERSIONS)))
-	define line =
+    define line =
 	Your compiler version, GCC $(version), is not supported by the Makefile.
 	The Makefile will assume GCC $(LATEST_GCC_VERSION).))
-	endef
+    endef
    $(call print,$(line))
    GCC$(subst .,,$(LATEST_GCC_VERSION))=1
   else