Added conversion for tournament from form

gaming-api/src/main/java/cz/muni/fi/pa165/dto/MatchDTO.java

@@ -23,4 +23,6 @@ public class MatchDTO extends BaseDTO {
     private Set<TeamEntity> teams = new HashSet<>();
 
     private Set<PlayerEntity> players = new HashSet<>();
+
+    private String tournamentId;
 }

gaming-spring-mvc/src/main/webapp/WEB-INF/jsp/match/new.jsp

@@ -13,12 +13,12 @@
         <div class="form-group">
             <form:label path="tournament" cssClass="col-sm-2 control-label">Tournament</form:label>
             <div class="col-sm-10">
-                <form:select path="tournament" required="required" cssClass="form-control">
+                <form:select path="tournamentId" required="required" cssClass="form-control">
                     <c:forEach items="${tournaments}" var="t">
-                        <form:option value="${t}">${t.id}</form:option>
+                        <form:option value="${t.id}">${t.id}</form:option>
                     </c:forEach>
                 </form:select>
-                <form:errors path="tournament" cssClass="error"/>
+                <form:errors path="tournamentId" cssClass="error"/>
             </div>
         </div>
         <div class="form-group">