less spawns xterm instead of showing contents (mailcap with $DISPLAY)

$ rpm -q mailcap lesspipe elinks
mailcap-2.3-5.noarch
lesspipe-1.47-1.noarch
package elinks is not installed

$ touch /tmp/lala.html
$ less /tmp/lala.html

# now xterm is spawned with contents:
/usr/bin/xterm: Can't execvp /usr/bin/elinks: No such file or directory

if that xterm is exited, less continues to work, i.e displays file contents

lesspipe should filter contents, not spawn GUI programs