don't write .cfg files of size 0

git-svn-id: svn://svn.code.sf.net/p/actiongame/code/trunk/ac@2381 e016b1c5-ed68-44aa-a2f7-31cac88cffde

source/src/worldio.cpp

@@ -127,6 +127,7 @@ uchar *readmap(char *name, int *size)
 
 void writecfg(char *name, int size, uchar *data)
 {
+    if (!size) return;
     setnames(name);
     FILE *f = openfile(mcfname, "w");
     if(!f) { conoutf("\f3could not write config to %s", mcfname); return; }