Revert "Bump the injected nREPL version"

This reverts commit 1f02fdc.

Author: alexander-yakushev

cider.el

@@ -518,7 +518,7 @@ Throws an error if PROJECT-TYPE is unknown."
   "List of dependencies where elements are lists of artifact name and version.")
 (put 'cider-jack-in-dependencies 'risky-local-variable t)
 
-(defcustom cider-injected-nrepl-version "1.6.0-alpha1"
+(defcustom cider-injected-nrepl-version "1.5.2"
   "The version of nREPL injected on jack-in.
 We inject the newest known version of nREPL just in case
 your version of Leiningen is bundling an older one."