In the event an import file isn't an msf_zip, pcapfile, and doesn't have a newline, bail.

git-svn-id: file:///home/svn/framework3/trunk@12465 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/core/db.rb

@@ -2100,6 +2100,7 @@ class DBManager
 		end
 
 		di = data.index("\n")
+		raise DBImportError.new("Could not automatically determine file type") unless di
 		firstline = data[0, di]
 		@import_filedata ||= {}
 		if (firstline.index("<NeXposeSimpleXML"))