[shotwell] meson: Fix missing libm for transitions

[Jens Georg <jensgeorg src gnome org>]

commit af1125c277a37f6e76887f148d424be5f37310ea
Author: Jens Georg <mail jensge org>
Date:   Wed Jun 21 19:49:54 2017 +0200

    meson: Fix missing libm for transitions
    
    https://bugzilla.gnome.org/show_bug.cgi?id=783956

 plugins/shotwell-transitions/meson.build |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/plugins/shotwell-transitions/meson.build b/plugins/shotwell-transitions/meson.build
index 1e7510a..8134292 100644
--- a/plugins/shotwell-transitions/meson.build
+++ b/plugins/shotwell-transitions/meson.build
@@ -14,10 +14,13 @@ shotwell_transitions_sources = [
 shotwell_transitions_resources = gnome.compile_resources('transitions-resource',
         'org.gnome.Shotwell.Transitions.gresource.xml')
 
+cc = meson.get_compiler('c')
+libm = cc.find_library('m', required : false)
+
 shared_module('shotwell-transitions',
               shotwell_transitions_sources + shotwell_transitions_resources,
               dependencies : [gio, gdk_pixbuf, cairo, gtk, gdk, xml, sw_plugin,
-                              sw_plugin_common_dep, gee, soup, webkit],
+                              sw_plugin_common_dep, gee, soup, webkit, libm],
               vala_args : [
                   '--gresources', 'org.gnome.Shotwell.Transitions.gresource.xml',
                   ],