configure: change gmime version in help message to 2.6

Since GMime 2.6 is now the stable version upstream, and probably the
most tested by notmuch developers, it makes sense to suggest that to
users to install.

diff --git a/configure b/configure
index ace465ba4ebfdee60a011ab7775501a01c76805a..71981b7c614a58f6b916acd49cf6515253dce396 100755 (executable)
--- a/configure
+++ b/configure
@@ -427,7 +427,7 @@ case a simple command will install everything you need. For example:
 
 On Debian and similar systems:
 
-       sudo apt-get install libxapian-dev libgmime-2.4-dev libtalloc-dev
+       sudo apt-get install libxapian-dev libgmime-2.6-dev libtalloc-dev
 
 Or on Fedora and similar systems: