Merge pull request #3621 from gubatron/build-osx-qt-dependency-missing

added missing homebrew qt dependency on mac osx build documentation.

Author: gavinandresen

doc/build-osx.md

@@ -69,7 +69,7 @@ Instructions: Homebrew
 
 #### Install dependencies using Homebrew
 
-        brew install autoconf automake berkeley-db4 boost miniupnpc openssl pkg-config protobuf
+        brew install autoconf automake berkeley-db4 boost miniupnpc openssl pkg-config protobuf qt
 
 Note: After you have installed the dependencies, you should check that the Homebrew installed version of OpenSSL is the one available for compilation. You can check this by typing