[REEF-2068] Bugfix: change_version.py fails on file build.DotNet.props (#1507)

We no longer have the build.DotNet.props file in our system.
The script should update the file lang/cs/build.Common.props instead.

JIRA: [REEF-2068](https://issues.apache.org/jira/projects/REEF/issues/REEF-2068)
diff --git a/dev/change_version.py b/dev/change_version.py
index cbe2fee..a9636aa 100644
--- a/dev/change_version.py
+++ b/dev/change_version.py
@@ -147,7 +147,7 @@
     f.close()
 
 """
-Change Version in lang/cs/build.DotNet.props
+Change Version in lang/cs/build.Common.props
 """
 def change_dotnet_props_cs(file, new_version):
     changed_str = ""
@@ -360,8 +360,8 @@
         change_project_number_Doxyfile(reef_home + "/Doxyfile", new_version)
         print reef_home + "/Doxyfile"
 
-        change_dotnet_props_cs(reef_home + "/lang/cs/build.DotNet.props", new_version)
-        print reef_home + "/lang/cs/build.DotNet.props"
+        change_dotnet_props_cs(reef_home + "/lang/cs/build.Common.props", new_version)
+        print reef_home + "/lang/cs/build.Common.props"
 
         change_reef_on_spark_scala(reef_home + "/lang/scala/reef-examples-scala/src/main/scala/org/apache/reef/examples/hellospark/ReefOnSpark.scala", new_version)
         print reef_home + "/lang/scala/reef-examples-scala/src/main/scala/org/apache/reef/examples/hellospark/ReefOnSpark.scala"