docs: drop deprecated doxygen TCL_SUBST flag

notmuch has no tcl code, and doxygen upstream is deprecating/removing
tcl support anyway:
https://github.com/doxygen/doxygen/commit/48a7afc0caf69857a42b0fe1963db3440cb4000f

diff --git a/doc/doxygen.cfg b/doc/doxygen.cfg
index a2c4fd07400c9e0bdbfd885062c0531ee649dbd0..4a022de1ce9ea1fa6c3c09280c8f83289c81147a 100644 (file)
--- a/doc/doxygen.cfg
+++ b/doc/doxygen.cfg
@@ -27,7 +27,6 @@ INHERIT_DOCS           = YES
 SEPARATE_MEMBER_PAGES  = NO
 TAB_SIZE               = 8
 ALIASES                =
-TCL_SUBST              =
 OPTIMIZE_OUTPUT_FOR_C  = YES
 OPTIMIZE_OUTPUT_JAVA   = NO
 OPTIMIZE_FOR_FORTRAN   = NO