Symbol#to_proc: fix with arrays of arrays

Previously, with nested arrays, the Symbol#to_proc would iterate over
the first item in the nested array instead of the array itself, e.g.:

[[1,2], [3,4]].map(&:first) #=>
	NoMethodError: undefined method `first' for 1:Fixnum

Library/Homebrew/extend/symbol.rb

@@ -1,5 +1,5 @@
 class Symbol
   def to_proc
-    proc { |obj, *args| obj.send(self, *args) }
+    proc { |*args| args.shift.send(self, *args) }
   end unless method_defined?(:to_proc)
 end