Fix inconsistent handling of --nopygrub parameter

Closes: https://bugs.debian.org/842609

hooks/common/80-install-modules-deb

@@ -31,7 +31,7 @@ fi
 #
 logMessage Script $0 starting
 
-if [ ${pygrub} ]; then
+if [ "${pygrub}" = "1" ]; then
     logMessage "pygrub set, skipping module install"
 else
 #

hooks/common/82-install-grub-legacy

@@ -26,7 +26,7 @@ fi
 #
 logMessage Script $0 starting
 
-if [ ${pygrub} ]; then
+if [ "${pygrub}" = "1" ]; then
 
 #
 #  Install the grub 0.9x package ("grub-legacy" on Debian, "grub" on Ubuntu)

hooks/debian/80-install-kernel

@@ -21,7 +21,7 @@ else
     . ./hooks/common.sh
 fi
 
-if [ "${pygrub}" ]; then
+if [ "${pygrub}" = "1" ]; then
 #
 # Log our start
 #

hooks/edgy/80-install-kernel

@@ -27,7 +27,7 @@ fi
 
 logMessage Script $0 starting
 
-if [ "${pygrub}" ]; then
+if [ "${pygrub}" = "1" ]; then
 
 #
 # Attempt to install a xen kernel, if that fails, then install a normal one

hooks/intrepid/80-install-kernel

@@ -27,7 +27,7 @@ fi
 
 logMessage Script $0 starting
 
-if [ "${pygrub}" ]; then
+if [ "${pygrub}" = "1" ]; then
 
 #
 # Attempt to install a xen kernel, if that fails, then install a normal one

hooks/karmic/80-install-kernel

@@ -26,7 +26,7 @@ fi
 
 logMessage Script $0 starting
 
-if [ "${pygrub}" ]; then
+if [ "${pygrub}" = "1" ]; then
 
 #
 # The type of kernel that we will be installing