One and a half stars. Rated R. 92 minutes. In the age of social media, is being alone the ultimate horror? The mildly creepy thriller “Friend Request” takes Facebook anxiety and turns it into a supernatural nightmare. While that’s not a bad idea for a thriller, this footage is unlikely to go viral. Laura (Alycia Debnam-Carey of “Fear the Walking Dead”) is a popular college student who has a smile for everybody.