misc: Fixed typo in iOS error message.

src/misc/ios/SDL_sysurl.m

@@ -29,7 +29,7 @@ int SDL_SYS_OpenURL(const char *url)
         NSString *nsstr = [NSString stringWithUTF8String:url];
         NSURL *nsurl = [NSURL URLWithString:nsstr];
         if (![[UIApplication sharedApplication] canOpenURL:nsurl]) {
-            return SDL_SetError("No handler registerd for this type of URL");
+            return SDL_SetError("No handler registered for this type of URL");
         }
         if (@available(iOS 10.0, tvOS 10.0, *)) {
             [[UIApplication sharedApplication] openURL:nsurl options:@{} completionHandler:^(BOOL success) {}];