local.conf.sample: Update sstate url to new 'all' path

(From meta-yocto rev: bfd62a1b09c46919ec4e3bc804d6f5634773cdda)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-poky/conf/local.conf.sample

@@ -230,7 +230,7 @@ BB_DISKMON_DIRS ??= "\
 # Note: For this to work you also need hash-equivalence passthrough to the matching server
 #
 #BB_HASHSERVE_UPSTREAM = "typhoon.yocto.io:8687"
-#SSTATE_MIRRORS ?= "file://.* http://sstate.yoctoproject.org/4.0/PATH;downloadfilename=PATH"
+#SSTATE_MIRRORS ?= "file://.* http://sstate.yoctoproject.org/all/PATH;downloadfilename=PATH"
 
 #
 # Qemu configuration