Makefile.defs: version set to 4.3.0-pre0

- pre-release phase - testing period, no new features till branching 4.3

Makefile.defs

@@ -97,7 +97,7 @@ INSTALL_FLAVOUR=$(FLAVOUR)
 VERSION = 4
 PATCHLEVEL = 3
 SUBLEVEL =  0
-EXTRAVERSION = -dev5
+EXTRAVERSION = -pre0
 
 # memory manager switcher
 # 0 - f_malloc (fast malloc)