switch off scheduler_doforcesplit by default, as this can cause problems elsewhere.

Former-commit-id: 8f2faf23a60506cf0ae04b5a3998e7d3658480bb

src/scheduler.h

@@ -24,7 +24,7 @@
 #define scheduler_dosub                      1
 #define scheduler_maxsteal                   10
 #define scheduler_maxtries                   2
-#define scheduler_doforcesplit               1
+#define scheduler_doforcesplit               0
 
 /* Flags . */
 #define scheduler_flag_none                  0