Fix error with double occurence of encoding declaration
Fix error with double occurence of encoding declaration

If a file sets the encoding using both vim and emacs style we can't
compile the source-code. This commit ensures that always both
occurences are removed before we compile the source-code.

nedbat/coveragepy,hugovk/coveragepy,blueyed/coveragepy,nedbat/coveragepy,blueyed/coveragepy,hugovk/coveragepy,blueyed/coveragepy,hugovk/coveragepy,blueyed/coveragepy,blueyed/coveragepy,nedbat/coveragepy,nedbat/coveragepy,hugovk/coveragepy,hugovk/coveragepy,nedbat/coveragepy