Message clean-up

*Changes:*

* "… is not yet properly setup" in line 24 is changed to " … is not yet set up properly" (better word order and space in the middle of "set up", as it is a participle of the verb "to set up").
* "internet" is corrected to "Internet" with a capitalized "I" in lines 54 and 59.
* Also in line 54: "3rd party" is changed to "third-party" to for a more coherent spelling across the different ownCloud components.
* "… apps don´t work" is corrected to "… apps won't work" (with a proper (and hopefully correctly escaped) (apostrophe)[http://en.wikipedia.org/wiki/Apostrophe#Typographic_form] instead of the (acute accent)[http://en.wikipedia.org/wiki/Acute_accent]).
* Still in line 54: The negation is corrected from "… might also not work" to "… might not work, either".