Fix the boot issue for pfSense 2.7.x (#2775)

INSTALL/grub/grub.cfg

@@ -516,6 +516,13 @@ function ventoy_freebsd_proc {
         fi
     fi
 
+    if [ "$vt_freebsd_ver" = "14.x" ]; then
+        if [ -e (loop)/boot/lua/brand-pfSense.lua ]; then
+            set vtFreeBsdDistro=pfSense
+        fi
+    fi
+
+
     if [ -n "${vtdebug_flag}" ]; then
         echo "This is $vtFreeBsdDistro $vt_freebsd_ver ${vt_freebsd_bit}bit"
     fi