Version bump to 3.1.18

This is neccessary because the commit:
a0883f36

Has a very large impact on bug reports. We need to have our
users check easily if they have that commit or not.

CMakeLists.txt

@@ -13,7 +13,7 @@ endif()
 
 set(KLEOPATRA_VERSION_MAJOR "3")
 set(KLEOPATRA_VERSION_MINOR "1")
-set(KLEOPATRA_VERSION_MICRO "17")
+set(KLEOPATRA_VERSION_MICRO "18")
 
 set(kleopatra_version "${KLEOPATRA_VERSION_MAJOR}.${KLEOPATRA_VERSION_MINOR}.${KLEOPATRA_VERSION_MICRO}.${KDE_APPLICATIONS_COMPACT_VERSION}")
 # The following is for Windows