open: B_ALREADY_RUNNING is valid for BUrl::OpenWithPreferredApplication().

Caused `open` to display an error with non-zero exit code when the
target application was already running and is single launch. In fact,
the error check at the end explicitly tests for B_ALREADY_RUNNING
along with B_OK.

Change-Id: Ic38c961bcdd8350b97b0d75ec010d25198afd561

src/bin/open.cpp

@@ -97,8 +97,8 @@ main(int argc, char** argv)
 		} else if (strchr(*argv, ':')) {
 			// try to open it as an URI
 			BUrl url(*argv);
-			if (url.OpenWithPreferredApplication() == B_OK) {
-				result = B_OK;
+			result = url.OpenWithPreferredApplication();
+			if (result == B_OK || result == B_ALREADY_RUNNING)
 				continue;
 			}