Fix substitutions

src/freedombone-app-nextcloud

 
         # remove any invalid characters
         if [ ${#NEXTCLOUD_TITLE} -gt 0 ]; then
-            new_title=${"$NEXTCLOUD_TITLE"//\'//}
+            new_title=${NEXTCLOUD_TITLE//\'/}
             NEXTCLOUD_TITLE="$new_title"
         fi
 

src/freedombone-app-pleroma

 
         # remove any invalid characters
         if [ ${#PLEROMA_TITLE} -gt 0 ]; then
-            new_title=${"$PLEROMA_TITLE"//\'//}
+            new_title=${PLEROMA_TITLE//\'/}
             PLEROMA_TITLE="$new_title"
         fi
 

src/freedombone-app-postactiv

 
         # remove any invalid characters
         if [ ${#POSTACTIV_TITLE} -gt 0 ]; then
-            new_title=${"$POSTACTIV_TITLE"//\'/}
+            new_title=${POSTACTIV_TITLE//\'/}
             POSTACTIV_TITLE="$new_title"
         fi