Stop publishing swt tools feature source

Tycho/PDE handle including sources without it just fine and next major
Tycho plans to drop the support for source features.

Author: akurtakov

eclipse.platform.releng.tychoeclipsebuilder/eclipse.platform.repository/category.xml

@@ -8,7 +8,6 @@
    <feature id="org.eclipse.equinox.sdk" version="0.0.0"/>
    <feature id="org.eclipse.sdk.examples.source" version="0.0.0"/>
    <feature id="org.eclipse.swt.tools.feature" version="0.0.0"/>
-   <feature id="org.eclipse.swt.tools.feature.source" version="0.0.0"/>
    <feature id="org.eclipse.equinox.executable" version="0.0.0"/>
    <feature id="org.eclipse.sdk" version="0.0.0"/>
    <feature id="org.eclipse.e4.core.tools.feature.source" version="0.0.0"/>