build: clean up sphinx.config

Follow the existing practice and remove it under "distclean", same as
sh.config and Makefile.config

diff --git a/Makefile.local b/Makefile.local
index 156c8ce13a808e534b900980d619b3adea8ed152..c65cee7cb15c1ae72ddaeca34060f07a86429ba1 100644 (file)
--- a/Makefile.local
+++ b/Makefile.local
@@ -294,7 +294,7 @@ CLEAN := $(CLEAN) notmuch notmuch-shared $(notmuch_client_modules)
 CLEAN := $(CLEAN) version.stamp notmuch-*.tar.gz.tmp
 CLEAN := $(CLEAN) .deps
 
-DISTCLEAN := $(DISTCLEAN) .first-build-message Makefile.config sh.config
+DISTCLEAN := $(DISTCLEAN) .first-build-message Makefile.config sh.config sphinx.config
 
 CPPCHECK_STAMPS := $(SRCS:%=.stamps/cppcheck/%)
 .PHONY: cppcheck