added hints to sql injection assignment 4 & 5, minor text changes to be consistent to other assignments

webgoat-lessons/sql-injection/src/main/resources/i18n/WebGoatLabels.properties

@@ -33,6 +33,10 @@ SqlStringInjectionHint2a1=You want the data from the column with the name depart
 SqlStringInjectionHint2a2=SELECT column FROM tablename WHERE condition;
 SqlStringInjectionHint3a1=Try the UPDATE statement
 SqlStringInjectionHint3a2=UPDATE tablename SET columnname=value WHERE condition;
+SqlStringInjectionHint4a1=ALTER TABLE alters the structure of an existing database
+SqlStringInjectionHint4a2=Don't forget the data type of the new column (e.g. varchar(size) or int(size))
+SqlStringInjectionHint4a3=ALTER TABLE tablename ADD columnname data type(size);
+SqlStringInjectionHint5a1=Look at the example. There's everything you'll need.
 SqlStringInjectionHint6=Try Appending a new SQL Statement to the Query.
 SqlStringInjectionHint7=The new SQL Statement can be really simple like: SELECT ... FROM ...
 SqlStringInjectionHint8=Your new SQL Query should start, with a " ; " and end with " -- "