fix forgotten "Mp"->"mp" rename in configure.ac

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@7734 2fb0f335-1f38-0410-981e-8018bf24f1b0

configure.ac

@@ -58,7 +58,7 @@ AC_CONFIG_FILES([dumux.pc
     dumux/material/fluidmatrixinteractions/Makefile 
     dumux/material/fluidmatrixinteractions/2p/Makefile 
     dumux/material/fluidmatrixinteractions/3p/Makefile 
-    dumux/material/fluidmatrixinteractions/Mp/Makefile 
+    dumux/material/fluidmatrixinteractions/mp/Makefile 
     dumux/material/spatialparameters/Makefile 
     dumux/material/fluidstates/Makefile 
     dumux/material/fluidsystems/Makefile