Fix typo in README.

7 jobs for readme in 13 minutes and 42 seconds (queued for 1 minute and 57 seconds)
latest
Status Name Job ID Coverage
  Build
passed build-debian-clang #183096
librem5

00:03:12

passed build-debian-gcc #183094
librem5

00:02:17

passed build-debian-gcc-static #183095
librem5

00:02:06

passed build-fedora-gcc #183097
librem5

00:03:59

 
  Docs
passed build-gtkdoc #183098
librem5

00:02:19

 
  Test
passed unit-test #183099
librem5

00:02:13

46.6%
 
  Package
passed package-debian #183100
librem5

00:02:50