Specify ignored bitcoin-qt file precisely

This commit prevents ignoring the build_msvc/bitcoin-qt directory.

Author: hebasto

.gitignore

@@ -90,7 +90,7 @@ src/qt/bitcoin-qt.includes
 *.qm
 Makefile
 !depends/Makefile
-bitcoin-qt
+src/qt/bitcoin-qt
 Bitcoin-Qt.app
 background.tiff*