Replace http://man7.org links with https://man7.org links.

I suspect the way http:// dies is that browsers just interpret it as
https:// anyway, but there's no reason not to just bulk fix all these at
source.

Change-Id: I38fa91728846d7c33207ef1bdadd4910eac9e941
diff --git a/libc/include/link.h b/libc/include/link.h
index ee1fc42..216502e 100644
--- a/libc/include/link.h
+++ b/libc/include/link.h
@@ -99,7 +99,7 @@
 };
 
 /**
- * [dl_iterate_phdr(3)](http://man7.org/linux/man-pages/man3/dl_iterate_phdr.3.html)
+ * [dl_iterate_phdr(3)](https://man7.org/linux/man-pages/man3/dl_iterate_phdr.3.html)
  * calls the given callback once for every loaded shared object. The size
  * argument to the callback lets you determine whether you have a smaller
  * `dl_phdr_info` from before API level 30, or the newer full one.