Fix typo in PQconnectStartParams().

This would lead to leaking the PGconn structure after an error detected by
conninfo_array_parse(), as well as failing to return a useful error message
in such cases.  Backpatch to 9.0 where the error was introduced.

Joseph Adams

src/interfaces/libpq/fe-connect.c

@@ -491,7 +491,7 @@ PQconnectStartParams(const char **keywords,
 	{
 		conn->status = CONNECTION_BAD;
 		/* errorMessage is already set */
-		return false;
+		return conn;
 	}
 
 	/*