fix issue that if functional block is dragged from project panel into
ST text editor and in dialog 'Please enter a block name' button
'cancel' is pressed, despite of cancel text about drag'n'dropped type
is pasted in ST program.

                  <xsd:element name="Linux">
                    <xsd:complexType>
                      %(toolchain_gcc)s
                    </xsd:complexType>
                  </xsd:element>