Fix up @carols10cents' mailmap entry

The previous ways didn't work; this does.

cc rust-lang-nursery/thanks#45

Author: steveklabnik

.mailmap

@@ -43,8 +43,8 @@ Brian Anderson <banderson@mozilla.com> <andersrb@gmail.com>
 Brian Dawn <brian.t.dawn@gmail.com>
 Brian Leibig <brian@brianleibig.com> Brian Leibig <brian.leibig@gmail.com>
 Carl-Anton Ingmarsson <mail@carlanton.se> <ca.ingmarsson@gmail.com>
-Carol (Nichols || Goulding) <carol.nichols@gmail.com> Carol Nichols <carol.nichols@gmail.com>
-Carol (Nichols || Goulding) <carol.nichols@gmail.com> Carol Nichols <cnichols@thinkthroughmath.com>
+Carol (Nichols || Goulding) <carol.nichols@gmail.com>
+Carol (Nichols || Goulding) <cnichols@thinkthroughmath.com>
 Carol Willing <carolcode@willingconsulting.com>
 Chris C Cerami <chrisccerami@users.noreply.github.com> Chris C Cerami <chrisccerami@gmail.com>
 Chris Pressey <cpressey@gmail.com>