Fix #including a definition that has local variables with proplists

The missing break meant that the freshly created copy of the proplist would
get overwritten by the original, which was thankfully caught and announced
with "internal error: constant proplist has the wrong parent".

Thanks to Zapper for the testcase.

planet/Tests.ocf/IncludeTest.ocs/Dummy.ocd/DefCore.txt

@@ -0,0 +1,7 @@
+[DefCore]
+id=DummyParent
+Version=5,3,0,0
+Category=C4D_StaticBack
+Width=8
+Height=8
+Offset=-4,-4

planet/Tests.ocf/IncludeTest.ocs/Dummy.ocd/Script.c

@@ -0,0 +1,13 @@
+local ActMap=
+{
+	Attach = 
+	{
+		Prototype = Action,
+		Name="Attach",
+		Procedure=DFA_ATTACH,
+		NextAction="Be",
+		Length=1,
+		FacetBase=1,
+		AbortCall = "AttachTargetLost"
+	}
+};

planet/Tests.ocf/IncludeTest.ocs/Dummy.ocd/StringTblDE.txt

@@ -0,0 +1 @@
+Name=Dummy

planet/Tests.ocf/IncludeTest.ocs/Dummy.ocd/StringTblUS.txt

@@ -0,0 +1 @@
+Name=Dummy

planet/Tests.ocf/IncludeTest.ocs/DummyChild.ocd/DefCore.txt

@@ -0,0 +1,7 @@
+[DefCore]
+id=DummyChild
+Version=5,3,0,0
+Category=C4D_StaticBack
+Width=8
+Height=8
+Offset=-4,-4

planet/Tests.ocf/IncludeTest.ocs/DummyChild.ocd/Script.c

@@ -0,0 +1,2 @@
+
+#include DummyParent

planet/Tests.ocf/IncludeTest.ocs/DummyChild.ocd/StringTblDE.txt

@@ -0,0 +1 @@
+Name=Dummy

planet/Tests.ocf/IncludeTest.ocs/DummyChild.ocd/StringTblUS.txt

@@ -0,0 +1 @@
+Name=Dummy

planet/Tests.ocf/IncludeTest.ocs/Scenario.txt

@@ -0,0 +1 @@
+ 

src/script/C4AulParse.cpp

@@ -2900,6 +2900,7 @@ void C4ScriptHost::CopyPropList(C4Set<C4Property> & from, C4PropListStatic * to)
 					}
 				to->SetPropertyByS(prop->Key, C4VPropList(p));
 			}
+			break;
 		case C4V_Array: // FIXME: copy the array if necessary
 		default:
 			to->SetPropertyByS(prop->Key, prop->Value);