feat(7z): complete h i and rn commands

These were added to the help output of p7zip 15.09 and are present in
all versions of 7zz.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

Author: kevinoid

completions/7z

@@ -6,7 +6,7 @@ _7z()
     _init_completion -n = || return
 
     if ((cword == 1)); then
-        COMPREPLY=($(compgen -W 'a b d e l t u x' -- "$cur"))
+        COMPREPLY=($(compgen -W 'a b d e h i l rn t u x' -- "$cur"))
         return
     fi