gphoto2: Move the sed op on config.h to do_compile

Current code still fails on some AB nodes.

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-graphics/gphoto2/gphoto2_2.5.28.bb

@@ -19,6 +19,6 @@ EXTRA_OECONF += "--with-jpeg-prefix=${STAGING_INCDIR} \
                  --without-cdk \
 "
 
-do_configure:append() {
-	sed -i -E "s/--sysroot=[^'\" ]+//g" ${B}/config.h
+do_compile:prepend() {
+	sed -i -e 's/--sysroot=[^ "]*//g' ${B}/config.h
 }