Standardise on British spelling: initialize -> initialise

OpenFOAM is predominantly written in Britain with British spelling conventions
so -ise is preferred to -ize.

src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.C

@@ -654,7 +654,7 @@ bool Foam::functionObjectList::read()
     bool ok = true;
     updated_ = execution_;
 
-    // Avoid reading/initializing if execution is off
+    // Avoid reading/initialising if execution is off
     if (!execution_)
     {
         return true;