[gthumb] meson: search lex if flex is not found

[Paolo Bacchilega <paobac src gnome org>]

commit 4afb8f194165204fed1afc8bb5bef886205b26f9
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Mon Oct 23 10:52:43 2017 +0200

    meson: search lex if flex is not found

 meson.build |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/meson.build b/meson.build
index 88503ed..5d82ed6 100644
--- a/meson.build
+++ b/meson.build
@@ -199,7 +199,7 @@ endif
 # web albums
 
 bison = find_program('bison', required : false)
-flex = find_program('flex', required : false)
+flex = find_program('flex', 'lex', required : false)
 with_webalbums = bison.found() and flex.found()
 
 vector_ops = (c_comp.get_id() == 'gcc') and (c_comp.version().version_compare('>=4.0.7'))