Fix bug in db_nmap with RDS

The cmd_db_nmap method was cleaning up the nmap XML file
before it could be read. Making the call synchronous will prevent
it from hitting the ensure block before the processing is done
when running msfdb locally.

Author: jbarnett-r7

lib/metasploit/framework/data_service/remote/http/remote_nmap_data_service.rb

@@ -14,6 +14,6 @@ def import_nmap_xml_file(opts)
 
     opts[:data] = Base64.urlsafe_encode64(data)
 
-    self.post_data_async(NMAP_PATH, opts)
+    self.post_data(NMAP_PATH, opts)
   end
 end