Move initialization to the initialization list

When the object of a class is created, the constructors of all member
variables are called consecutively in the order the variables are declared,
even if we don't explicitly write them to the initialization list.

lib/ShellCommand.cpp

@@ -59,9 +59,8 @@ ShellCommand::ShellCommand(const QString & fullCommand)
     }
 }
 ShellCommand::ShellCommand(const QString & command , const QStringList & arguments)
+    : _arguments(arguments)
 {
-    _arguments = arguments;
-
     if ( !_arguments.isEmpty() ) {
         _arguments[0] = command;
     }