L10N: Don't translate strings that dont contain any alphabetic character

Per 0penBrain's suggestion

src/Mod/Part/Gui/DlgSettings3DViewPart.ui

@@ -56,7 +56,7 @@
         <item row="0" column="1">
          <widget class="Gui::PrefDoubleSpinBox" name="maxDeviation">
           <property name="suffix">
-           <string> %</string>
+           <string notr="true"> %</string>
           </property>
           <property name="decimals">
            <number>4</number>
@@ -91,7 +91,7 @@
         <item row="1" column="1">
          <widget class="Gui::PrefDoubleSpinBox" name="maxAngularDeflection">
           <property name="suffix">
-           <string> °</string>
+           <string notr="true"> °</string>
           </property>
           <property name="decimals">
            <number>2</number>

src/Mod/Part/Gui/DlgSettingsObjectColor.ui

@@ -90,7 +90,7 @@
            <string>The default transparency for new shapes</string>
           </property>
           <property name="suffix">
-           <string>%</string>
+           <string notr="true">%</string>
           </property>
           <property name="maximum">
            <number>100</number>

src/Mod/Part/Gui/SectionCutting.ui

@@ -339,7 +339,7 @@ Works only if all objects have the same values.</string>
          <bool>false</bool>
         </property>
         <property name="toolTip">
-         <string>0 %</string>
+         <string notr="true">0 %</string>
         </property>
         <property name="maximum">
          <number>100</number>