Update centos.sh

scripts/install/centos.sh

@@ -93,6 +93,7 @@ fi
 
 if [ -f /www/server/mdserver-web/bin/activate ];then
     cd /www/server/mdserver-web && source /www/server/mdserver-web/bin/activate && pip3 install -r /www/server/mdserver-web/requirements.txt
+    pip install --upgrade pip
     pip3 install gunicorn==20.1.0
 	pip3 install gevent==21.1.2
 	pip3 install gevent-websocket==0.10.1
@@ -103,6 +104,7 @@ if [ -f /www/server/mdserver-web/bin/activate ];then
 	pip3 install pymongo
 else
     cd /www/server/mdserver-web && pip3 install -r /www/server/mdserver-web/requirements.txt
+    pip install --upgrade pip
     pip3 install gunicorn==20.1.0
 	pip3 install gevent==21.1.2
 	pip3 install gevent-websocket==0.10.1