Remove unused externalized text "submodulesNotSupported"

This text is unused since d72b9328.

Change-Id: I82e5652e205d7b238ff8adc21994029b828b09f4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java

@@ -729,7 +729,6 @@ public class JGitText extends TranslationBundle {
 	/***/ public String submoduleNameInvalid;
 	/***/ public String submoduleParentRemoteUrlInvalid;
 	/***/ public String submodulePathInvalid;
-	/***/ public String submodulesNotSupported;
 	/***/ public String submoduleUrlInvalid;
 	/***/ public String supportOnlyPackIndexVersion2;
 	/***/ public String systemConfigFileInvalid;