fix: update script: non-standard version numbers

store version output in new variable
slice output indexed from beginning instead of end. allowing for custom
build version numbers.

also fix weird spacing from tabs being two spaces wide, sorry :)

scripts/upgrade-server.sh

@@ -35,12 +35,13 @@ url=`curl -s https://api.github.com/repos/writeas/writefreely/releases/latest |
 
 # check current version
 
-current=`./writefreely -v`
+bin_output=`./writefreely -v`
-if [ -z "$current" ]; then
+if [ -z "$bin_output" ]; then
 	exit 1
 fi
 
-echo "Current version is v${current:(-5):5}"
+current=${bin_output:12:5}
+echo "Current version is v$current"
 
 # grab latest version number
 IFS='/'
@@ -51,7 +52,7 @@ echo "Latest release is $latest"
 
 
 IFS='.'
-read -ra cv <<< "${current:(-5):5}"
+read -ra cv <<< "$current"
 read -ra lv <<< "${latest#v}"
 
 IFS=' '