fix(server): prevent adding logs to non-existent repo

src/db/git.v

@@ -152,3 +152,11 @@ pub fn (db &VieterDb) update_git_repo_archs(repo_id int, archs []GitRepoArch) {
 		}
 	}
 }
+
+pub fn (db &VieterDb) git_repo_exists(repo_id int) bool {
+	db.get_git_repo(repo_id) or {
+		return false
+	}
+	
+	return true
+}