Revert CentOS 6 and CentOS 7

public/detect_linux.sh

@@ -8,18 +8,7 @@ function resetDistVer {
   DISTVER=
 }
 
-if [ -f /etc/centos-release ]; then
-  . /etc/os-release
-  if [ "$VERSION_ID" == "7" ]; then
-    DISTNAME=centos
-    DISTVER=7
-  elif [ "$VERSION_ID" == "6" ]; then
-    DISTNAME=centos
-    DISTVER=6
-  else
-    resetDistVer
-  fi
-elif [ -f /etc/fedora-release ]; then
+if [ -f /etc/fedora-release ]; then
   . /etc/os-release
   if [ "$VERSION_ID" == "29" ]; then
     DISTNAME=fedora