component/trafficserver: fix ncurses detection

This was building against system library when ncurses-dev system
package is installed

component/trafficserver/buildout.cfg

@@ -48,7 +48,8 @@ patches =
   ${:_profile_base_location_}/trafficserver-9.1.1-via-string-rapid-cdn.patch#8c39243d7525222385d5964485734f99
 environment =
   PATH=${libtool:location}/bin:${make:location}/bin:${patch:location}/bin:${perl:location}/bin:${pkgconfig:location}/bin:%(PATH)s
-  LDFLAGS =-L${openssl:location}/lib -Wl,-rpath=${openssl:location}/lib -L${tcl:location}/lib -Wl,-rpath=${tcl:location}/lib -L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${luajit:location}/lib  -lm
+  LDFLAGS =-L${openssl:location}/lib -Wl,-rpath=${openssl:location}/lib -L${tcl:location}/lib -Wl,-rpath=${tcl:location}/lib -L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${luajit:location}/lib -L${ncurses:location}/lib -Wl,-rpath=${ncurses:location}/lib -lm
+  CURSES_CFLAGS=-I${ncurses:location}/include
 
 make-target =
   check