install_amavis.sh: some minor changes..

install_amavis.sh

@@ -3299,6 +3299,18 @@ if $INSTALL_CLAMAV_UNOFFICIAL_SIGS ; then
    if [[ "$?" -ne 0 ]] ; then
       installation_failed=true
       error "$(cat $tmp_err_msg)"
+
+      warn "command was:
+
+                     git clone https://github.com/extremeshok/clamav-unofficial-sigs.git /tmp/clamav-unofficial-sigs"
+		echononl "continue anyway [yes/no]: "
+		read OK
+		OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+		while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+			echononl "Wrong entry! - repeat [yes/nno]: "
+			read OK
+		done
+		[[ $OK = "yes" ]] || fatal "Abbruch durch User"
    fi
    if ! $installation_failed ; then
       echo_ok