[#115] apemanager: Fix type getters

* Add type instance check for nil to avoid panic by
  accessing fields.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

ape/types.go

@@ -53,6 +53,10 @@ func (c *Chain) SetKind(kind chainKind) {
 }
 
 func (c *Chain) GetKind() chainKind {
+	if c == nil {
+		return nil
+	}
+
 	return c.kind
 }
 
@@ -67,5 +71,9 @@ func (c *ChainRaw) SetRaw(raw []byte) {
 }
 
 func (c *ChainRaw) GetRaw() []byte {
+	if c == nil {
+		return nil
+	}
+
 	return c.Raw
 }