Fix compilation warning of pg_basebackup with MinGW
Several buildfarm members have been complaining about that with gcc,
like jacana.  Weirdly enough, Visual Studio's compilers do not find this
issue.
Author: Michael Paquier
Discussion:
@@ -1445,7 +1445,9 @@ ReceiveAndUnpackTarFile(PGconn *conn, PGresult *res, int rownum)
if (file == NULL)
{
+#ifndef WIN32
int filemode;
+#endif
/*
* No current file, so this must be the header for a new file
@@ -1459,8 +1461,10 @@ ReceiveAndUnpackTarFile(PGconn *conn, PGresult *res, int rownum)
current_len_left = read_tar_number(&copybuf[124], 12);
+#ifndef WIN32
/* Set permissions on the file */
filemode = read_tar_number(&copybuf[100], 8);
+#endif
/*
* All files are padded up to 512 bytes
