AMBARI-12625. Update LICENSE file to address SIL Open Source License for FontAwesome. (yusaku)

LICENSE.txt

@@ -782,4 +782,9 @@ e) to display the Original Work publicly.
 
 15) Right to Use. You may use the Original Work in all ways not otherwise restricted or conditioned by this License or by law, and Licensor promises not to interfere with or be responsible for such uses by You.
 
-This license is Copyright (C) 2003-2004 Lawrence E. Rosen. All rights reserved. Permission is hereby granted to copy and distribute this license without modification. This license may not be modified without the express written permission of its copyright owner.
+This license is Copyright (C) 2003-2004 Lawrence E. Rosen. All rights reserved. Permission is hereby granted to copy and distribute this license without modification. This license may not be modified without the express written permission of its copyright owner.
+
+
+This product uses software based on SIL Open Font License (OFL)
+* Font-Awesome (SIL OFL 1.1) [http://fortawesome.github.io/Font-Awesome/]
+