[SalesForce] apex:inputFile can not be used in conjunction with an action component

I am getting the below error while saving the data. Please let me know where i am doing wrong –

apex:inputFile can not be used in conjunction with an action
component, apex:commandButton or apex:commandLink that specifies a
rerender or oncomplete attribute.

public void UploadPhoto(){

            try{

                con.Name= conlastname;  
                con.First_Name__c= conemail;
                con.Family_Name__c= conphone;
                con.Gender__c= conmobilephone;
                con.Email__c = mail;
                insert con;


                Attachment a = this.tAttachment.clone(false, true, false, false);
                a.OwnerId = UserInfo.getUserId();
                a.ParentId = con.id;
                this.tAttachment.Body = null;
                insert a;

                message = ApexPages.AddMessage(new ApexPages.Message(ApexPages.Severity.CONFIRM,'Record Created Successfully.Thank you!'));

            }catch(Exception e){
                system.debug('Exception message'+e);
            }
            return null;
    }

Vf Page –

<apex:page standardController="Devotee__c" sidebar="false" extensions="devoteeinsert" showHeader="false">    
    <style type="text/css">
       .img{width:100px !important;} 
       .bPageBlock .detailList tr td, .bPageBlock .detailList tr th, .hoverDetail .bPageBlock .detailList tr td, .hoverDetail .bPageBlock .detailList tr th { border-bottom: none !important;}
       .OptPanel{width:50%;float:left;padding-top:20px;borde:none !important; }   
       .Optpanel1{float:right;padding-right:100px;}   
       .bPageBlock, .individualPalette .bPageBlock
       {
            border: none !important;
           background:none !important;
       }

    </style>
    <apex:stylesheet value="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" />
    <apex:includeScript value="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"/>
    <apex:form >
        <apex:pageMessages id="showmsg"></apex:pageMessages>
         <fieldset>
            <legend>Devotee Registration</legend>
                <apex:outputpanel layout="block" styleclass="OptPanel">

                    </apex:pageblock>
               </apex:outputpanel>
                <apex:outputpanel layout="block" styleclass="Optpanel1">
                    <apex:pageblock mode="maindetail" >           
                        <apex:pageblocksection columns="1" >

                          <apex:inputFile value="{!tAttachment.Body}" filename="{!tAttachment.Name}" filesize="{!tAttachment.BodyLength}" contentType="{!tAttachment.ContentType}" />
                              <apex:commandButton value="Save Data" action="{!uploadphoto}" rerender="showmsg" />                                    
                        </apex:pageblocksection>

                    </apex:pageblock>
                 </apex:outputpanel>
           </fieldset>
    </apex:form>
</apex:page>