Remove incorrect Germanic SpecificName

The SpecificName tag is meant to contain the name in the civ's native
language, Proto-Germanic for the Germans.
"Kriegsschiff", "Übungsbereich" and "Stadttor" on the other hand are
modern German words.

(cherry picked from commit a71688fc2c)
Signed-off-by: phosit <phosit@autistici.org>

binaries/data/mods/public/simulation/templates/structures/germ/range.xml

@@ -2,7 +2,6 @@
 <Entity parent="template_structure_military_range">
   <Identity>
     <Civ>germ</Civ>
-    <SpecificName>Übungsbereich</SpecificName>
   </Identity>
   <VisualActor>
     <Actor>structures/germans/range.xml</Actor>

binaries/data/mods/public/simulation/templates/structures/germ/wall_gate.xml

@@ -6,7 +6,6 @@
   </Footprint>
   <Identity>
     <Civ>germ</Civ>
-    <SpecificName>Stadttor</SpecificName>
   </Identity>
   <Obstruction>
     <Obstructions>

binaries/data/mods/public/simulation/templates/units/germ/ship_arrow.xml

@@ -6,7 +6,6 @@
   </Footprint>
   <Identity>
     <Civ>germ</Civ>
-    <SpecificName>Kriegsschiff</SpecificName>
     <Icon>units/germ/ship_arrow.png</Icon>
   </Identity>
   <VisualActor>