wic: encode help text

Encoded help text before sending it to pager.communicate as
it expects binary.

[YOCTO #9412]

(From OE-Core rev: 23c27d9d936efaa17da00525f1d2e2f98c53abc7)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/wic/help.py

@@ -45,7 +45,7 @@ def display_help(subcommand, subcommands):
     if callable(hlp):
         hlp = hlp()
     pager = subprocess.Popen('less', stdin=subprocess.PIPE)
-    pager.communicate(hlp)
+    pager.communicate(hlp.encode('utf-8'))
 
     return True