man/img2webp.1: fix formatting warning
the default is format is roman, fixes:
`R' is a string (producing the registered sign), not a macro.
.\" Hey, EMACS: -*- nroff -*-
-.TH IMG2WEBP 1 "December 1, 2016"
+.TH IMG2WEBP 1 "January 23, 2017"
.SH NAME
img2webp \- create animated WebP file from a sequence of input images.
.SH SYNOPSIS
.B img2webp
-.R [file_level_options] [files] [per_frame_options...]
+[file_level_options] [files] [per_frame_options...]
.br
.SH DESCRIPTION
This manual page documents the
