Clean up tag links only in "Tags:" line

The bug was that if you decide, for some reason, insert links to tag pages
into text of your article, then after editing this article, the links were
gone. That happened because "tag links cleaning" was too agressive (it was
cleaning tags not only on tag line, but in the whole text)

bb.sh

@@ -362,7 +362,7 @@ edit() {
         # Title
         echo "$(get_post_title $1)" > "$TMPFILE"
         # Post text with plaintext tags
-        get_html_file_content 'text' 'text' <$1 | sed "s|<a href='$prefix_tags\([^']*\).html'>\\1</a>|\\1|g" >> "$TMPFILE"
+        get_html_file_content 'text' 'text' <$1 | sed "/^<p>$template_tags_line_header/s|<a href='$prefix_tags\([^']*\).html'>\\1</a>|\\1|g" >> "$TMPFILE"
         rm $1
         $EDITOR "$TMPFILE"
         if [ "$2" = "keep" ]; then