update buildscript

build.sh

@@ -2,8 +2,8 @@
 
 cp config.mk patches.h dwm-flexipatch/
 flexipatch-finalizer/flexipatch-finalizer.sh -r -d dwm-flexipatch -o dwm-final
-rm dwm-flexipatch/config.mk dwm-flexipatch/patches.h
-for patch in patches/*.patch; do
+git -C dwm-flexipatch reset --hard HEAD && git -C dwm-flexipatch clean -fd
+for patch in patches/*.diff; do
 	patch -d dwm-final <"$patch"
 done
 cp config.h dwm-final/