Resolve "Email link to settings is hardcoded"

Closes #57 (closed)

src/main/java/nl/tudelft/submit/controller/StudentGroupController.java

@@ -25,6 +25,7 @@ import java.util.stream.Collectors;
 import javax.transaction.Transactional;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
@@ -49,6 +50,9 @@ import nl.tudelft.submit.service.*;
 @Controller
 public class StudentGroupController {
 
+	@Value("${submit.domain}")
+	private String domain;
+
 	@Autowired
 	private AuthorizationService authorizationService;
 
@@ -103,8 +107,7 @@ public class StudentGroupController {
 		SubmitGroupDetailsDTO group = groupService.getSubmitGroupDetails(id.getId());
 
 		// set up Message Members feature
-		Map<String, Object> variableMap = new HashMap<>();
-		variableMap.put("message", "");
+		Map<String, Object> variableMap = Map.of("message", "", "domain", domain);
 
 		MailMessageCreateDTO mailDto = MailMessageCreateDTO
 				.builder()