add http2 support

src/libsync/owncloudpropagator.cpp

@@ -74,8 +74,17 @@ OwncloudPropagator::~OwncloudPropagator()
 /* The maximum number of active jobs in parallel  */
 int OwncloudPropagator::maximumActiveJob()
 {
-    // this will be parallelised to 100 by hardMaximumActiveJob for files < 100kB
-    return 50;
+    static int max = qgetenv("OWNCLOUD_MAX_PARALLEL").toUInt();
+    if (!max) {
+        max = 3; //default
+    }
+
+    if (_downloadLimit.fetchAndAddAcquire(0) != 0 || _uploadLimit.fetchAndAddAcquire(0) != 0) {
+        // disable parallelism when there is a network limit.
+        return 1;
+    }
+
+    return max;
 }
 
 int OwncloudPropagator::hardMaximumActiveJob()