Fix bug in install script

Author: jaapmarcus

install/hst-install-debian.sh

@@ -1593,7 +1593,7 @@ if [ "$exim" = 'yes' ]; then
     gpasswd -a Debian-exim mail > /dev/null 2>&1
     exim_version=$(exim4 --version |  head -1 | awk  '{print $3}' | cut -f -2 -d .);
     if [ "$exim_version" = "4.94" ]; then
-      cp -f $HESTIA_INSTALL_DIR/exim/exim4.conf.4.94.template /etc/exim/exim4.conf.template
+      cp -f $HESTIA_INSTALL_DIR/exim/exim4.conf.4.94.template /etc/exim4/exim4.conf.template
     else
       cp -f $HESTIA_INSTALL_DIR/exim/exim4.conf.template /etc/exim4/
     fi