Remove duplicated port setting (#128)

diff --git a/docker-compose/Makefile b/docker-compose/Makefile
index edb55d6..67855c0 100644
--- a/docker-compose/Makefile
+++ b/docker-compose/Makefile
@@ -131,7 +131,7 @@
 .PHONY: check-required-ports
 check-required-ports:
 	echo "checking required ports ... "
-	for port in 2888 5984 8085 8888 9092 2888 8001; do \
+	for port in 2888 5984 8085 8888 9092 8001; do \
 		pid=`lsof -Pi :$$port -sTCP:LISTEN -t` ; \
 		if [ ! -z "$$pid" ];  then echo "$$(tput setaf 1)Port $$port is taken by PID:$$pid.$$(tput sgr0)"; exit 1; fi; \
 	done