Autotools: Fix initial build configuration setup

Trade a duplicated 'make' for a 'make clean' step.

Amends 571fb04d.

Change-Id: I06dca803715a5c0a1a0917e4a4d5bac5704e8a43
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotoolsprojectmanager/autotoolsbuildconfiguration.cpp

@@ -68,7 +68,7 @@ public:
         appendInitialBuildStep(Constants::MAKE_STEP_ID); // make
 
         // ### Build Steps Clean ###
-        appendInitialBuildStep(Constants::MAKE_STEP_ID);
+        appendInitialCleanStep(Constants::MAKE_STEP_ID); // make clean
     }
 };