Reduce flush blocks count to avoid OOM due to massive state cleanup u…

…pdates

ethereumj-core/src/main/resources/ethereumj.conf

@@ -294,7 +294,7 @@ cache {
         memory = 0
 
         # [10000 flush each 10000 blocks]
-        blocks = 1000
+        blocks = 100
     }
 }