popup vs pop-up in source language .pot file

There are inconsistencies in this pot file. Most times the word popup is used but there are 2 instances of pop-up as indicated below. These should be changed to popup, as indicated in "preferred" below, for consistency.

Original.
#: ../src/capplet/mate-notification-properties.desktop.in.h:1
msgid "Pop-Up Notifications"
msgstr ""

#: ../src/capplet/mate-notification-properties.desktop.in.h:2
msgid "Set your pop-up notification preferences"
msgstr ""

Preferred.
#: ../src/capplet/mate-notification-properties.desktop.in.h:1
msgid "Popup Notifications"
msgstr ""

#: ../src/capplet/mate-notification-properties.desktop.in.h:2
msgid "Set your popup notification preferences"
msgstr ""

This is my 1st pull request, if I've done it wrong let me know.