bump version to 1.5.2

diff --git a/Makefile b/Makefile
index 06b6da5..cc81238 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 1
 PATCHLEVEL = 5
-SUBLEVEL = 1
+SUBLEVEL = 2
 EXTRAVERSION =
 NAME = Unnamed