Fix a broken link

Author: komainu8

_es/overviews/parallel-collections/ctries.md

@@ -164,5 +164,5 @@ en paralelo.
 3. [Methods of computing square roots][3]
 
   [1]: https://infoscience.epfl.ch/record/166908/files/ctries-techreport.pdf "Ctries-techreport"
-  [2]: https://lampwww.epfl.ch/~prokopec/ctries-snapshot.pdf "Ctries-snapshot"
+  [2]: http://lampwww.epfl.ch/~prokopec/ctries-snapshot.pdf "Ctries-snapshot"
   [3]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method "babylonian-method"