fix(log): Disallow multi-logging

Make logging options mutually-exclusive to avoid confusion.

.idea/misc.xml

@@ -2,7 +2,7 @@
 <project version="4">
   <component name="com.itcodebox.notebooks.projectservice.ProjectUIState">
     <option name="selectedNotebookId" value="1" />
-    <option name="selectedChapterId" value="1" />
-    <option name="selectedNoteId" value="1" />
+    <option name="selectedChapterId" value="2" />
+    <option name="selectedNoteId" value="2" />
   </component>
 </project>

cfddns.sh

@@ -207,9 +207,9 @@ writeLog() {
   PT_LOG_LEVEL="$(standardizeLogLevels "$2")"
   ([ "$logDebug" -eq 0 ] && [ "$PT_LOG_LEVEL" = "DEBUG" ]) && return
 
-  ([ "$logToJournal" -eq 1 ]) && writeJournalDLog "$@"
-  ([ "$useJsonLogFmt" -eq 1 ]) && writeJsonLog "$@"
-  ([ "$useSyslogLogFmt" -eq 1 ]) && writePlainTextLog "$@"
+  ([ "$logToJournal" -eq 1 ]) && writeJournalDLog "$@" && return
+  ([ "$useJsonLogFmt" -eq 1 ]) && writeJsonLog "$@" && return
+  ([ "$useSyslogLogFmt" -eq 1 ]) && writePlainTextLog "$@" && return
 }
 
 scriptExamples() {