gitignore: remove explicit config.h references

config.h is ignored by a global match.
Signed-off-by: Anders Darander <anders@chargestorm.se>

.gitignore

@@ -26,9 +26,6 @@ Makefile.in
 configure
 aclocal.m4
 
-DSLogic-gui/config.h
 DSLogic-gui/ui_*.h
 DSLogic-gui/DSLogic
 
-libsigrok4DSLogic/config.h
-