Fix Mac build issue

Default data dir path used "Bitcoin" instead of "MultiChain".

Author: simon

src/utils/utilwrapper.cpp

@@ -298,7 +298,7 @@ boost::filesystem::path mc_GetDefaultDataDir()
     // Mac
     pathRet /= "Library/Application Support";
     TryCreateDirectory(pathRet);
-    return pathRet / "Bitcoin";
+    return pathRet / "MultiChain";
 #else
     // Unix
     return pathRet / ".multichain";
@@ -930,4 +930,4 @@ int mc_FindIPv4ServerAddress(uint32_t *all_ips,int max_ips)
     return c;
 }
 
-        
+