allow creating empty ZIP archives (patch 1861030)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@50992 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/zipstrm.cpp

@@ -2287,7 +2287,7 @@ bool wxZipOutputStream::Close()
 {
     CloseEntry();
 
-    if (m_lasterror == wxSTREAM_WRITE_ERROR || m_entries.size() == 0) {
+    if (m_lasterror == wxSTREAM_WRITE_ERROR) {
         wxFilterOutputStream::Close();
         return false;
     }