update os/os_version explorer to support owl (openwall linux)

Signed-off-by: Nico Schottelius <nico@kr.ethz.ch>

conf/explorer/os

@@ -65,7 +65,7 @@ if [ -f /etc/SuSE-release ]; then
    exit 0
 fi
 
-if uname -r | grep -s '.owl' >/dev/null 2>&1; then
+if [ -f /etc/owl-release ]; then
    echo owl
    exit 0
 fi

conf/explorer/os_version

@@ -42,6 +42,9 @@ case "$($__explorer/os)" in
    *bsd|solaris)
       uname -r
    ;;
+   owl)
+      cat /etc/owl-release
+   ;;
    redhat|centos)
       cat /etc/redhat-release
    ;;