Update URL following merge into platform of other repos

Amongst possibly other things I think this is the URL
that is embedded in MANFIFEST.MF as the location the bundles
are stored in git. The proper value for this comes from
the parent pom.

debug/pom.xml

@@ -23,10 +23,6 @@
   <artifactId>eclipse.platform.debug</artifactId>
   <packaging>pom</packaging>
 
-  <properties>
-    <tycho.scmUrl>scm:git:https://github.com/eclipse-platform/eclipse.platform.debug.git</tycho.scmUrl>
-  </properties>
-
   <modules>
     <module>org.eclipse.core.externaltools</module>
     <module>org.eclipse.core.variables</module>

runtime/pom.xml

@@ -21,10 +21,6 @@
   <artifactId>eclipse.platform.runtime</artifactId>
   <packaging>pom</packaging>
 
-   <properties>
-     <tycho.scmUrl>scm:git:https://github.com/eclipse-platform/eclipse.platform.git</tycho.scmUrl>
-  </properties>
-
   <modules>
     <module>bundles</module>
     <module>features/org.eclipse.core.runtime.feature</module>

ua/pom.xml

@@ -21,9 +21,6 @@
   <groupId>eclipse.platform.ua</groupId>
   <artifactId>eclipse.platform.ua</artifactId>
   <packaging>pom</packaging>
-  <properties>
-    <tycho.scmUrl>scm:git:https://github.com/eclipse-platform/eclipse.platform.ua.git</tycho.scmUrl>
-  </properties>
 
   <!-- 
     To build individual bundles, we specify a repository where to find parent pom,