Fixed environment chop -> chomp issue which truncated single character e...

A conditional using a "chop" on the environment string was not allowing the use of single character environment names within chef-client inputted from the command line with "-E". For instance, "chef-client -E d" would not work as expected since the chop would truncate the "d" to an empty string. This is fixed by using "chomp" instead of "chop" which only eliminates separator characters.