fixed new day offset default value

uhabits-android/src/main/res/values/strings.xml

@@ -219,7 +219,7 @@
     <string name="example_question_boolean">e.g. Did you exercise today?</string>
     <string name="question">Question</string>
     <string name="target">Target</string>
-    <string name="day_hour_offset_default">15</string>
+    <string name="day_hour_offset_default">-15</string>
     <string name="day_hour_offset">Day starting hour</string>
     <string name="pref_new_day_offset_title">Day starting hour</string>
 </resources>

uhabits-android/src/main/res/xml/preferences.xml

@@ -115,23 +115,6 @@
             android:key="pref_new_day_offset"
             android:summary="%s"
             android:title="@string/pref_new_day_offset_title" />
-
-
-
-
-        <!--<EditTextPreference-->
-            <!--android:defaultValue="3"-->
-            <!--android:dialogTitle="hours_offset"-->
-            <!--android:inputType="phone"-->
-            <!--android:key="hours_offset"-->
-            <!--android:digits="0123456789"-->
-            <!--android:selectAllOnFocus="true"-->
-            <!--android:summary="hours_offset"-->
-            <!--android:title="hours_offset" />-->
-        <!--&lt;!&ndash;android:maxLength="2"&ndash;&gt;-->
-        <!--&lt;!&ndash;android:numeric="integer"&ndash;&gt;-->
-
-
     </PreferenceCategory>
 
     <PreferenceCategory