Fix pmd warnings

src/main/java/at/ac/uibk/gitsearch/service/GitlabService.java

@@ -146,7 +146,11 @@ public class GitlabService {
             file =
                 gitLabApi
                     .getRepositoryFileApi()
-                    .getFile(Long.valueOf(exercise.getProject().getProjectId()), filePath, exercise.getFile().getCommit_id());
+                    .getFile(
+                        Long.valueOf(exercise.getProject().getProjectId()),
+                        exerciseId.extendPath(filePath),
+                        exercise.getFile().getCommit_id()
+                    );
             return new ByteArrayInputStream(file.getDecodedContentAsBytes());
         } catch (GitLabApiException e) {
             log.warn(
@@ -168,7 +172,11 @@ public class GitlabService {
                     gitLabRepository
                         .getAdminGitLabApi()
                         .getRepositoryFileApi()
-                        .getFile(Long.valueOf(exercise.getProject().getProjectId()), filePath, exercise.getFile().getCommit_id());
+                        .getFile(
+                            Long.valueOf(exercise.getProject().getProjectId()),
+                            exerciseId.extendPath(filePath),
+                            exercise.getFile().getCommit_id()
+                        );
 
                 return new ByteArrayInputStream(file.getDecodedContentAsBytes());
             }