make enum reading from the db more robust

src/constants.rs

@@ -18,6 +18,12 @@ pub enum MoveState {
     Moving = 3,
 }
 
+impl Default for MoveState {
+    fn default() -> Self {
+        MoveState::Undefined
+    }
+}
+
 // some defaults
 const DC_E2EE_DEFAULT_ENABLED: i32 = 1;
 pub const DC_MDNS_DEFAULT_ENABLED: i32 = 1;
@@ -220,6 +226,12 @@ pub enum Viewtype {
     File = 60,
 }
 
+impl Default for Viewtype {
+    fn default() -> Self {
+        Viewtype::Unknown
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;