Fix checkstyle

Author: jovyntls

src/main/java/seedu/address/logic/parser/AddressBookParser.java

@@ -2,6 +2,7 @@
 
 import static seedu.address.commons.core.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
 import static seedu.address.commons.core.Messages.MESSAGE_UNKNOWN_COMMAND;
+
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;