Update FastPFor to upstream master

fastpfor/Makefile

@@ -1,8 +1,8 @@
 SHELL:=/bin/bash
 
 caf:
-	git clone https://github.com/rayburgemeestre/FastPFor
-	pushd FastPFor && git checkout master
+	git clone https://github.com/lemire/FastPFor
+	pushd FastPFor && git checkout 8030e3808f857cc12d1d09e264f1ad2a05b1964a # master at the time of writing
 	bash ../ubuntu1804.sh make impl
 	make package