Tripped by comments before pragmas

[nomeata]

It seems that extensions can be thown off by comments before the pragma list, as in these files:

• http://hackage.haskell.org/package/executable-path-0.0.3.1/docs/src/System-Environment-Executable.html
• http://hackage.haskell.org/package/extra-1.6.8/docs/src/Data.Tuple.Extra.html

(small selection… I am running your tool on all hackage package’s latest versions, so I can provide more.)