BareMetal: Allow omitting OpenOCD config files

There seem to be uses of that case.

Task-number: QTCREATORBUG-18784
Change-Id: I2f278eab87406a3549c57b5fa032e9f3a606e947
Reviewed-by: Alexander Drozdov <adrozdoff@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/baremetal/openocdgdbserverprovider.cpp

@@ -164,7 +164,7 @@ bool OpenOcdGdbServerProvider::isValid() const
     }
 
     if (m == StartupOnNetwork || m == StartupOnPipe) {
-        if (m_executableFile.isEmpty() || m_configurationFile.isEmpty())
+        if (m_executableFile.isEmpty())
             return false;
     }