feat(conf): make compatible with old configurations

Author: lxcmyf

common/src/main/java/org/tron/core/Constant.java

@@ -39,7 +39,7 @@ public class Constant {
   public static final long MAX_CONTRACT_RESULT_SIZE = 2L;
   public static final long PB_DEFAULT_ENERGY_LIMIT = 0L;
   public static final long CREATOR_DEFAULT_ENERGY_LIMIT = 1000 * 10_000L;
-  public static final long MIN_PROPOSAL_VOTING_WINDOW = 0L; // ms
+  public static final long MIN_PROPOSAL_VOTING_WINDOW = 0L; // 0 ms
   public static final long MAX_PROPOSAL_VOTING_WINDOW = 31536000000L; // ms of 365 days
   /**
    * default number of blocks to 3 days