Fix HTMLElement subscript import into Swift by matching getter's type…

…s with those of the setter.

Apparently Swift needs the types to match. Oops!

Fixes nolanw#59.

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased][]
 
+* Fix `HTMLElement`'s subscripting abilities not getting bridged into Swift (issue #59 revisited).
+
 ## [1.0.1][]
 
 * Pass updated html5lib-tests.

Sources/include/HTMLElement.h

@@ -36,7 +36,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (readonly, copy, nonatomic) HTMLDictOf(NSString *, NSString *) *attributes;
 
 /// Returns the value of the named attribute, or nil if no such value exists.
-- (id __nullable)objectForKeyedSubscript:(id)attributeNameOrString;
+- (NSString * __nullable)objectForKeyedSubscript:(NSString *)attributeNameOrString;
 
 /// Sets a named attribute's value, adding it to the element if needed.
 - (void)setObject:(NSString *)attributeValue forKeyedSubscript:(NSString *)attributeName;