Update default config test.

Author: thedodd

rustfmt-core/rustfmt-config/src/lib.rs

@@ -519,6 +519,7 @@ reorder_impl_items = false
 type_punctuation_density = "Wide"
 space_before_colon = false
 space_after_colon = true
+space_around_attr_eq = true
 spaces_around_ranges = false
 binop_separator = "Front"
 remove_nested_parens = true