doc: fix typo

doc/startify.txt

@@ -177,7 +177,7 @@ It's because Vim loads the list from viminfo only once, at startup.
 "I use OSX and iTerm2 and have broken colors!"
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-Nothing this plugin could do about. Try playing round with 'sessionoptions'.
+Nothing this plugin could do about. Try playing around with 'sessionoptions'.
 Some people swear it works for them with these settings:
 
     set sessionoptions=blank,curdir,folds,help,tabpages,winpos