Apply shellcheck advices

install_yunohostv2

@@ -48,7 +48,7 @@ $1
 " 1>&2
     tput sgr 0
     notify_about_install_logs
-    exit ${2:-1}
+    exit "${2:-1}"
 }
 
 this_script_path() {
@@ -60,7 +60,7 @@ this_script_path() {
       [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE" # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located
     done
     DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
-    echo $DIR
+    echo "$DIR"
 }
 
 ensure_root() {
@@ -85,7 +85,7 @@ installscript_dependencies() {
         --                                           \
         apt-get -o Dpkg::Options::="--force-confold" \
                 -y install                           \
-                $packages                            \
+                "$packages"                          \
         || return 2
 
     return 0
@@ -148,7 +148,7 @@ setup_package_source() {
     echo "deb http://repo.yunohost.org/ megusta main" > $CUSTOMAPT
 
     # Also add repositories for 'testing' and/or 'unstable' if the script has been called with those arguments
-    if [[ "$#" > "0" ]]; then
+    if [[ "$#" -gt "0" ]]; then
         if [[ "$1" == "test" ]] || [[ "$1" == "testing" ]] ; then
             echo "deb http://repo.yunohost.org/ testing main" >> $CUSTOMAPT
         fi
@@ -172,9 +172,9 @@ apt_update() {
 register_debconf() {
     if [[ $(lsb_release -c | awk '{print $2}') == jessie ]];
     then
-        debconf-set-selections $(this_script_path)/debconfjessie
+        debconf-set-selections "$(this_script_path)/debconfjessie"
     else
-        debconf-set-selections $(this_script_path)/debconfv2
+        debconf-set-selections "$(this_script_path)/debconfv2"
     fi
 }
 
@@ -199,10 +199,10 @@ workaround_avahi_installation() {
     id avahi > /dev/null 2>&1 || return 0
  
     # Get a random unused uid between 500 and 999 (system-user) 
-    local avahi_id=$((500 + $RANDOM % 500))
-    while ! cat /etc/passwd | cut -d ':' -f 3 | grep -q $avahi_id ;
+    local avahi_id=$((500 + RANDOM % 500))
+    while ! cut -d ':' -f 3 /etc/passwd | grep -q $avahi_id ;
     do
-        avahi_id=$((500 + $RANDOM % 500))
+        avahi_id=$((500 + RANDOM % 500))
     done
 
     # Use the same adduser parameter as in the avahi-daemon postinst script