Increased numberOfAdditionalBatchesToSearch from 5 to 7.

This is the equivalent of increasing the max address gap from 15 to 21. The electrum standalone wallet uses 20, so this should be the most we will ever need.

src/main/java/org/qortal/crosschain/Bitcoiny.java

@@ -404,7 +404,7 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 			Set<String> keySet = new HashSet<>();
 
 			// Set the number of consecutive empty batches required before giving up
-			final int numberOfAdditionalBatchesToSearch = 5;
+			final int numberOfAdditionalBatchesToSearch = 7;
 
 			int unusedCounter = 0;
 			int ki = 0;