build: fix for older macOS versions

Fix build for macOS versions less than 10.14

Change-Id: I13a33a6e7b4edefb82a150b4947d58dccf71d69b
diff --git a/src/AccSipGeneralVC.mm b/src/AccSipGeneralVC.mm
index 4ae0247..1cd1a49 100644
--- a/src/AccSipGeneralVC.mm
+++ b/src/AccSipGeneralVC.mm
@@ -156,6 +156,7 @@
 - (IBAction)editPhoto:(id)sender
 {
     auto pictureTaker = [IKPictureTaker pictureTaker];
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 101400
     if (@available(macOS 10.14, *)) {
         AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
         if(authStatus == AVAuthorizationStatusRestricted || authStatus == AVAuthorizationStatusDenied)
@@ -172,6 +173,7 @@
             }];
         }
     }
+#endif
 
     [pictureTaker beginPictureTakerSheetForWindow:[self.view window]
                                      withDelegate:self