Merge pull request #332 from ostera/patch-1

Update sed.md

pages/common/sed.md

@@ -9,7 +9,7 @@
 - replace all occurrences of a string in a file, and overwrite the file
   contents
 
-`sed -i '' 's/{{find}}/{{replace}}/g' {{filename}}`
+`sed -i 's/{{find}}/{{replace}}/g' {{filename}}`
 
 - replace all occurrences of an extended regular expression in a file