disabled appending file with garbage when regexp didn't match.

When using lineinfile module, lines was appended with garbage when regular expression didn't match. 
Using example: lineinfile dest=/tmp/grub.conf state=present regexp='^(splashimage=.*)$' line="#\\1"
when regexp was not found originally lineinfile module would append file with "#\1". 
I believe better is do nothing if regexp returned false.