Fix PHP wrapper script in older Bash versions with intermediate var

Previously worked at least in Bash v5.2.15 but failed in v3.2.57. Now
works identically in both. Must be some minor difference in shell
interpolation, but this works regardless so the details aren't too
important.

Previous tweak here did fix the first replacement case (with :) but
didn't work for the second case, where it could replace to just php//php
for some reason.

Author: pimterry

overrides/path/php

@@ -8,8 +8,9 @@ PATH="`dirname "$0"`:$PATH"
 
 # Strip out our PHP_INI_SCAN_DIR - if this file has been run succesfully, then it's not necessary,
 # and it can cause problems (since it overrides any default scan directories configured)
-export PHP_INI_SCAN_DIR="${PHP_INI_SCAN_DIR//:`echo $HTTP_TOOLKIT_OVERRIDE_PATH`/php/}"
-export PHP_INI_SCAN_DIR="${PHP_INI_SCAN_DIR//`echo $HTTP_TOOLKIT_OVERRIDE_PATH`/php/}"
+export INJECTED_PHP_INI_DIR=$HTTP_TOOLKIT_OVERRIDE_PATH/php
+export PHP_INI_SCAN_DIR="${PHP_INI_SCAN_DIR//:$INJECTED_PHP_INI_DIR/}"
+export PHP_INI_SCAN_DIR="${PHP_INI_SCAN_DIR//$INJECTED_PHP_INI_DIR/}"
 if [ -z "$PHP_INI_SCAN_DIR" ]; then
     unset PHP_INI_SCAN_DIR
 fi