[tracker-miners] meson: Fix breakage when building with charset_detection=enca

[Sam Thursfield <sthursfield src gnome org>]

commit be1a5ff29066b7db2f5d2827080cae3ee5084c86
Author: Sam Thursfield <sam afuera me uk>
Date:   Sat Dec 16 14:20:05 2017 +0000

    meson: Fix breakage when building with charset_detection=enca

 meson.build |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/meson.build b/meson.build
index ecda78c..0caa2bc 100644
--- a/meson.build
+++ b/meson.build
@@ -158,7 +158,7 @@ else
   endif
 endif
 
-if charset_library_name == 'none' and get_option('charset_library') != 'none'
+if charset_library_name == 'none' and get_option('charset_detection') != 'none'
   enca = dependency('enca', version: '>= 1.9', required: false)
 
   if enca.found()