flex: fix aclocal-* errors by running autogen.sh

Signed-off-by: Alejandro Mery <amery@geeks.cl>

base/flex/flex.conf

@@ -24,4 +24,3 @@ hook_add postmake 5 "pkg_flex_postmake"
 hook_add preconf 5 "sed -i -e '/test-bison-yylloc/d' -e '/test-bison-yylval/d' tests/Makefile.in"
 # don't mix with host system
 var_append GCC_WRAPPER_REMOVE ' ' "-I/usr/include"
-

base/flex/flex.desc

@@ -33,4 +33,6 @@
 [V] 2.6.3
 [P] X 01-3-5---9 102.080
 
+[O] autogen=1
+
 [D] 1929379314 flex-2.6.3.tar.gz !https://github.com/westes/flex/releases/download/v2.6.3/flex-2.6.3.tar.gz