Use remove() then rename() only on win32 - where it's required.

Don't use it on unix systems, which don't need it, and where doing 
_only_ rename() preserves atomicity. 

svn path=/icecast/trunk/icecast/; revision=6625

src/auth.c

@@ -366,6 +366,7 @@ int auth_htpasswd_deleteuser(auth_t *auth, char *username)
     fclose(passwdfile);
 
     /* Now move the contents of the tmp file to the original */
+#ifdef _WIN32
     /* Windows won't let us rename a file if the destination file
        exists...so, lets remove the original first */
     if (remove(state->filename) != 0) {
@@ -373,11 +374,14 @@ int auth_htpasswd_deleteuser(auth_t *auth, char *username)
                 tmpfile, state->filename, strerror(errno));
     }
     else {
+#endif
         if (rename(tmpfile, state->filename) != 0) {
             ERROR3("Problem moving temp authentication file to original \"%s\" - \"%s\": %s", 
                 tmpfile, state->filename, strerror(errno));
 	}
+#ifdef _WIN32
     }
+#endif
 
     free(tmpfile);