change English wordings for the "no speed limits posted" confirmation…

… dialog (fixes #757)

app/src/main/res/values/strings.xml

@@ -213,9 +213,9 @@ If there are no signs along the whole street which apply for the highlighted sec
     <string name="quest_maxspeed_answer_noSign_confirmation_positive">"Yes, no sign"</string>
 
     <string name="quest_maxspeed_answer_noSign_info_urbanOrRural">"Where is this street?"</string>
-    <string name="quest_maxspeed_answer_noSign_urbanOrRural_description">Urban roads have a different default speed limit than rural roads.</string>
-    <string name="quest_maxspeed_answer_noSign_urbanOk">"In town"</string>
-    <string name="quest_maxspeed_answer_noSign_ruralOk">"Out of town"</string>
+    <string name="quest_maxspeed_answer_noSign_urbanOrRural_description">Roads in urban (in town or densely populated) areas have a different default speed limit than rural roads.</string>
+    <string name="quest_maxspeed_answer_noSign_urbanOk">"Urban"</string>
+    <string name="quest_maxspeed_answer_noSign_ruralOk">"Rural"</string>
     <string name="quest_maxspeed_answer_noSign_info_zone">"If there is a sign like this at the main street intersection, you won't find individual signs within the zone because the speed limit posted there applies to the whole zone."</string>
     <string name="quest_cyclewaySurface_title">"What surface does the cycleway here have?"</string>
     <string name="quest_cycleway_title">"Is there a cycleway in this street?"</string>