hooks: do not require MMDEBSTRAP_VERBOSITY to be set

This allows running the hook from older mmdebstrap versions.

hooks/busybox/extract00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/busybox/setup00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/eatmydata/customize.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/eatmydata/extract.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/file-mirror-automount/customize00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/file-mirror-automount/setup00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/merged-usr/essential00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
         set -x
 fi
 

hooks/merged-usr/setup00.sh

@@ -41,7 +41,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
 	set -x
 fi
 

hooks/no-merged-usr/essential00.sh

@@ -2,7 +2,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
         set -x
 fi
 

hooks/no-merged-usr/setup00.sh

@@ -11,7 +11,7 @@
 
 set -eu
 
-if [ "$MMDEBSTRAP_VERBOSITY" -ge 3 ]; then
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
         set -x
 fi