removed some duplicates

[silky]

Fixes #139

You can check for duplicates like so:

cat agda-input.vim | grep 'call' | sed 's/^.*(//' | sed 's/",.*$/"/' | uniq -D

I just deleted the first of all the mappings (as that one was never used anyway); but feel free to suggest changes and I can make them.

[isovector]

Thanks so much!