Add check for empty lines in DownloadManager

src/engine/downloadmanager.cpp

@@ -299,6 +299,12 @@ std::vector<std::shared_ptr<DownloadManager::FileFuture>> DownloadManager::downl
         std::string line;
         int nFiles = 0;
         while (std::getline(temporary, line)) {
+            if (line.empty()) {
+                // This might occur if someone added multiple newlines
+                // or mixing carriage return and newlines
+                continue;
+            }
+            
             ++nFiles;
 #ifdef __APPLE__
             // @TODO: Fix this so that the ifdef is not necessary anymore ---abock