fixed += for file statistics

Author: Lana243

server/src/printers/CoverageAndResultsStatisticsPrinter.cpp

@@ -89,8 +89,8 @@ namespace printer {
     FileCoverageAndResultsStatistics::operator+=(const FileCoverageAndResultsStatistics &other) {
         totalExecutionTime += other.totalExecutionTime;
         totalTestsNum += other.totalTestsNum;
-        for (auto &[status, testsNum]: testsWithStatusNum) {
-            testsNum += CollectionUtils::getOrDefault(other.testsWithStatusNum, status, 0u);
+        for (const auto &[status, testsNum] : other.testsWithStatusNum) {
+            testsWithStatusNum[status] += testsNum;
         }
         fullCoverageLinesNum += other.fullCoverageLinesNum;
         partialCoverageLinesNum += other.partialCoverageLinesNum;