Revert "Do not throw runtime error on parsing error"

This reverts commit 5e2cd0d.

client/client.cc

@@ -527,8 +527,7 @@ bool AutopowerClient::streamMeasurementData(std::string measId) {
       if (!couldParseTs) {
         delete gTimestamp;
         uploadWasSuccessful = false;
-        // throw std::runtime_error("Could not parse timestamp: " + ts);
-        break;
+        throw std::runtime_error("Could not parse timestamp: " + ts);
       }
 
       grpcMsmtSample.set_allocated_msmttime(gTimestamp); // grpc will free the object itself, so NO need to call free!