autoupdater: fix regression in version compare

Version strings with the same prefix, e.g. "1.0" and "1.0~pre", or even
"1.0" and "1.0.1" were considered equal. This is a regression in the C
autoupdater rewrite.

admin/autoupdater/src/version.c

@@ -47,7 +47,7 @@ bool newer_than(const char *a, const char *b) {
 	if (b == NULL)
 		return true;
 
-	while (*a != '\0' && *b != '\0') {
+	while (*a != '\0' || *b != '\0') {
 		int first_diff = 0;
 
 		// compare non-digits character by character