apr-util: workaround reconfigure issue

PKG_CONFIG_DEPENDS causes a rebuild when needed. Alas the apr-util build
system doesn't always work out the way OpenWrt intends it to. This was
found by pure chance. apr-util was in build directory without any
plugins selected. Then apache got selected, causing plugins to be
selected. So PKG_CONFIG_DEPENDS caused a reconfigure and another make in
apr-util. But afterward apache couldn't find symbols related to LDAP.

To workaround this add "clean" to make targets.

No rev bump because no change for the apr-util packages.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/apr-util/Makefile

@@ -126,6 +126,13 @@ endef
 $$(eval $$(call BuildPackage,libaprutil-$(subst _,-,$(1))))
 endef
 
+# PKG_CONFIG_DEPENDS trigger configure, but the compile afterward may be
+# incomplete if the build directory is not cleaned before. This is not a
+# general observation, yet it is valid for apr-util :/
+define Build/Compile
+	$(call Build/Compile/Default,clean all)
+endef
+
 define Build/InstallDev
 	$(INSTALL_DIR) $(1)/usr/bin $(1)/usr/include/apr-1 \
 				$(1)/usr/lib/pkgconfig