debian/control: Fix typo in newly added dependency for freerdp2-dev.
debian/control: Fix typo in newly added dependency for freerdp2-dev.

bmiklautz/debian-freerdp2,bmiklautz/debian-freerdp2,bmiklautz/debian-freerdp2,bmiklautz/debian-freerdp2,bmiklautz/debian-freerdp2,bmiklautz/debian-freerdp2