Fix regex to find DBFILE= from configuration file

The regex ^\s^.DBFILE\s*=\s* does not work to match "DBFILE="
I don't know what the second '^' is used for.

With the change I now have the results:

DBFILE=/foo/bar
-> /foo/bar

  DBFILE=/foo/bar
-> /foo/bar

 # DBFILE=/foo/bar
-> /etc/pihole/pihole-FTL.db

xDBFILE=/foo/bar
-> /etc/pihole/pihole-FTL.db

Signed-off-by: Ludovic Rousseau <ludovic.rousseau@free.fr>

advanced/Scripts/piholeLogFlush.sh

@@ -16,7 +16,7 @@ source ${colfile}
 # Constructed to return nothing when
 # a) the setting is not present in the config file, or
 # b) the setting is commented out (e.g. "#DBFILE=...")
-DBFILE="$(sed -n -e 's/^\s^.DBFILE\s*=\s*//p' /etc/pihole/pihole-FTL.conf)"
+DBFILE="$(sed -n -e 's/^\s*DBFILE\s*=\s*//p' /etc/pihole/pihole-FTL.conf)"
 # Test for empty string. Use standard path in this case.
 if [ -z "$DBFILE" ]; then
   DBFILE="/etc/pihole/pihole-FTL.db"