Bug 1151849

Description of problem:
While executing dnf langavailable <LANGNAME> it is showing warning

Version-Release number of selected component (if applicable):
dnf-langpacks-0.4.0-1.fc21.noarch

How reproducible:
Everytime

Steps to Reproduce:
1.dnf langavailable punjabi 
2.sudo dnf langavailable tamil
3.dnf langavailable hindi

Actual results:
Warning as below:

[aman@spacehawk ~]$ sudo dnf langavailable punjabi
/usr/lib/python2.7/site-packages/dnf-plugins/langpacks.py:381: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  if lang.lower() in list(map(str.lower, lang_list)):

punjabi is available
Dependencies resolved.
Nothing to do.
[aman@spacehawk ~]$ sudo dnf langavailable tamil
/usr/lib/python2.7/site-packages/dnf-plugins/langpacks.py:381: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  if lang.lower() in list(map(str.lower, lang_list)):

tamil is available
Dependencies resolved.
Nothing to do.
[aman@spacehawk ~]$ sudo dnf langavailable hindi
hindi is available
Dependencies resolved.
Nothing to do.


Expected results:
Should not be warning for Unicode like in case of Hindi

Additional info:
1. <LANGCODE> is working as expected, but only issue if there is LANG-NAME is used.

2. Warning is there for Few languages like Tamil, Telugu, but working fine for Gujarati, Malayalam, Assamese, Bengali etc.