fix: maxAssingments required property in MgmtSoftwareModuleTypeRequestBodyPost (#2671)

resolves #2669

hawkbit-mgmt/hawkbit-mgmt-api/src/main/java/org/eclipse/hawkbit/mgmt/json/model/softwaremoduletype/MgmtSoftwareModuleTypeRequestBodyPost.java

@@ -33,6 +33,7 @@ public class MgmtSoftwareModuleTypeRequestBodyPost extends MgmtSoftwareModuleTyp
     @Schema(example = "Example key")
     private String key;
 
+    @JsonProperty(required = true)
     @Schema(example = "1")
     private int maxAssignments;
 
@@ -47,4 +48,4 @@ public class MgmtSoftwareModuleTypeRequestBodyPost extends MgmtSoftwareModuleTyp
         super.setColour(colour);
         return this;
     }
-}
+}