Upgrade patchlevel to 1.5.2a1.
diff --git a/Include/patchlevel.h b/Include/patchlevel.h
index d6054c4..fec20e1 100644
--- a/Include/patchlevel.h
+++ b/Include/patchlevel.h
@@ -1 +1 @@
-#define PATCHLEVEL "1.5.1"
+#define PATCHLEVEL "1.5.2a1"