Set captures preferences for PREF_EFFECT_CAPTURE.

This is a simple example of changing preferences that don't
affect dissection to something else, so that changing them
doesn't cause a file to be redissected unnecessarily

Change-Id: I77c64c739e8bbc9f2a202f744f27cb07be4a822b
Reviewed-on: https://code.wireshark.org/review/25173
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Michael Mann <mmann78@netscape.net>

epan/prefs.c

@@ -3424,6 +3424,8 @@ prefs_register_modules(void)
      */
     capture_module = prefs_register_module(NULL, "capture", "Capture",
         "Capture preferences", NULL, FALSE);
+    /* Capture preferences don't affect dissection */
+    prefs_set_module_effect_flags(capture_module, PREF_EFFECT_CAPTURE);
 
     register_string_like_preference(capture_module, "device", "Default capture device",
         "Default capture device",

ui/qt/preferences_dialog.cpp

@@ -269,7 +269,7 @@ void PreferencesDialog::on_buttonBox_accepted()
 
     wsApp->setMonospaceFont(prefs.gui_qt_font_name);
 
-    if (must_redissect) {
+    if (must_redissect & PREF_EFFECT_DISSECTION) {
         /* Redissect all the packets, and re-evaluate the display filter. */
         wsApp->queueAppSignal(WiresharkApplication::PacketDissectionChanged);
     }

ui/qt/protocol_preferences_menu.cpp

@@ -276,6 +276,8 @@ void ProtocolPreferencesMenu::boolPreferenceTriggered()
         prefs_main_write();
     }
 
+    /* Protocol preference changes almost always affect dissection,
+       so don't bother checking flags */
     wsApp->emitAppSignal(WiresharkApplication::PacketDissectionChanged);
 }
 
@@ -292,6 +294,8 @@ void ProtocolPreferencesMenu::enumPreferenceTriggered()
             prefs_main_write();
         }
 
+        /* Protocol preference changes almost always affect dissection,
+           so don't bother checking flags */
         wsApp->emitAppSignal(WiresharkApplication::PacketDissectionChanged);
     }
 }