Fix undefined behavior found by GCC 5

GCC said:
qtldurl.cpp:51:50: error: loop exit may only be reached after undefined behavior [-Werror=aggressive-loop-optimizations]
qtldurl.cpp:51:48: note: possible undefined statement is here
     while (tldIndices[index] >= tldChunks[chunk] && chunk < tldChunkCount) {
                                                ^

That's because we check whether chunk is still valid (less than
tldChunkCount) after we've dereferenced tldChunks[chunk]. That is, we've
already read tldChunk[2].

Change-Id: I79b6a1ea9a2454813d6cce7596fc2bb6d972d097
Reviewed-by: David Faure <david.faure@kdab.com>

src/corelib/io/qtldurl.cpp

@@ -48,7 +48,7 @@ static bool containsTLDEntry(const QString &entry)
     // select the right chunk from the big table
     short chunk = 0;
     uint chunkIndex = tldIndices[index], offset = 0;
-    while (tldIndices[index] >= tldChunks[chunk] && chunk < tldChunkCount) {
+    while (chunk < tldChunkCount && tldIndices[index] >= tldChunks[chunk]) {
         chunkIndex -= tldChunks[chunk];
         offset += tldChunks[chunk];
         chunk++;