Fix qt unit test build on OSX

README.md

@@ -66,7 +66,7 @@ Unit tests for the GUI code are in `src/qt/test/`. To compile and run them:
 
     qmake BITCOIN_QT_TEST=1 -o Makefile.test bitcoin-qt.pro
     make -f Makefile.test
-    ./Bitcoin-Qt
+    ./bitcoin-qt_test
 
 Every pull request is built for both Windows and Linux on a dedicated server,
 and unit and sanity tests are automatically run. The binaries produced may be