[smuxi] configure.ac: bumped minimum required Mono version to 2.8 (refs: #1058)

[Mirco M. M. Bauer <mmmbauer src gnome org>]

commit d10feafd4ce65f9dff79fa4739e8fbaf8c4a78d0
Author: Mirco Bauer <meebey meebey net>
Date:   Sun Jun 14 21:33:12 2015 +0200

    configure.ac: bumped minimum required Mono version to 2.8 (refs: #1058)
    
    Mono 2.6.7 incorrectly de-serializes DateTime values sent over .NET remoting.
    Smuxi frontends sending DateTime values to a smuxi-server that runs on Mono
    2.6.7 will end up with a value that is off by the timezone offset. E.g.:
    2015-06-12T20:03:34.7553410Z on the frontend becomes
    2015-06-12T18:03:34.7553410Z on the server side if the timezone offset is +2
    
    This change is needed to really fix bff11a093e0e57184a54ee0860aa586036dd2746
    as with Mono 2.6.7 as smuxi-server still had the bug seen in #1058.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9f81336..7f9b1cc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -142,7 +142,7 @@ AC_SUBST([DEV_VERSION_SUFFIX])
 AC_SUBST([dist_version], "$DIST_VERSION")
 
 SHAMROCK_EXPAND_LIBDIR
-SHAMROCK_CHECK_MONO_MODULE(1.9.1)
+SHAMROCK_CHECK_MONO_MODULE(2.8)
 SHAMROCK_FIND_MONO_RUNTIME
 SHAMROCK_FIND_MONO_2_0_COMPILER_OR_HIGHER
 SHAMROCK_CHECK_MONO_2_0_GAC_ASSEMBLIES([