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

@@ -1,23 +1,23 @@
 #! /bin/bash
 ###############################################################################
-##											writefreely update script														 ##
+##			writefreely update script			     ##
-##																																					 ##
+##								 	     ##
-##		WARNING: running this script will overwrite any modifed assets or 		 ##
+##	WARNING: running this script will overwrite any modifed assets or    ##
-##		template files. If you have any custom changes to these files you 		 ##
+##	template files. If you have any custom changes to these files you    ##
-##		should back them up FIRST.																						 ##
+##	should back them up FIRST.					     ##
-##																																					 ##
+##									     ##
-##		This must be run from the web application root directory							 ##
+##	This must be run from the web application root directory	     ##
-##		i.e. /var/www/writefreely, and operates under the assumption that you  ##
+##	i.e. /var/www/writefreely, and operates under the assumption that you##
-##		have not installed the binary `writefreely` in another location.			 ##
+##	have not installed the binary `writefreely` in another location.     ##
 ###############################################################################
 #
-#			Copyright © 2019 A Bunch Tell LLC.
+#	Copyright © 2019 A Bunch Tell LLC.
 #
-#			This file is part of WriteFreely.
+#	This file is part of WriteFreely.
 #
-#			WriteFreely is free software: you can redistribute it and/or modify
+#	WriteFreely is free software: you can redistribute it and/or modify
-#			it under the terms of the GNU Affero General Public License, included
+#	it under the terms of the GNU Affero General Public License, included
-#			in the LICENSE file in this source code package.
+#	in the LICENSE file in this source code package.
 #
 
 
@@ -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=' '