Use ad hoc operator

src/const.ml

@@ -107,7 +107,7 @@ let rc_file_old =
   let internal_default : string lazy_t =
     (* Default value, if no value is given (for instance as
        command line argument), or no environnement variable is set *)
-    Lazy.(home >>| fun home -> home ^ "/" ^ ".oclaunch_rc.json")
+    Lazy.(home >>| fun home -> home ^/ ".oclaunch_rc.json")
   in
   get_var ~default:internal_default (lazy "OC_RC_OLD")
 ;;
@@ -117,7 +117,7 @@ let rc_file_default =
   let internal_default : string lazy_t =
     (* Default value, if no value is given (for instance as
        command line argument), or no environnement variable is set *)
-    Lazy.(home >>| fun home -> home ^ "/" ^ ".oclaunch_rc.scm")
+    Lazy.(home >>| fun home -> home ^/ ".oclaunch_rc.scm")
   in
   get_var ~default:internal_default (lazy "OC_RC")
 ;;