JDBC: Make MessageRowMapper as non-nullable

Even if `ResultSet.getBytes()` contract says that value might be null,
that is not waht is possible according to the message stores logic.
The vale for serialized `MESSAGE_BYTES` is never null.

Author: artembilan

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/store/channel/MessageRowMapper.java

@@ -18,6 +18,7 @@
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.Objects;
 
 import org.springframework.integration.support.converter.AllowListDeserializingConverter;
 import org.springframework.jdbc.core.RowMapper;
@@ -51,15 +52,9 @@ public MessageRowMapper(AllowListDeserializingConverter deserializer) {
 	}
 
 	@Override
-	@SuppressWarnings("NullAway") // See https://github.com/uber/NullAway/issues/1075
 	public Message<?> mapRow(ResultSet rs, int rowNum) throws SQLException {
 		byte[] blobAsBytes = rs.getBytes("MESSAGE_BYTES");
-		if (blobAsBytes == null) {
-			return null;
-		}
-		else {
-			return (Message<?>) this.deserializer.convert(blobAsBytes);
-		}
+		return (Message<?>) this.deserializer.convert(Objects.requireNonNull(blobAsBytes));
 	}
 
 }