Remove extraneous quotes from Windows env script

We quoted some strings in the Windows elasticsearch-env script but echo
on Windows includes these quotes in the output. This commit removes
these quotes, they do not need to be output and are noise. Note that one
of the commands is wrapped in parentheses, this is to make obvious that
the space at the end of the corresponding line is intentionally there.

distribution/src/main/resources/bin/elasticsearch-env.bat

@@ -30,14 +30,14 @@ if not exist %JAVA% (
 
 rem do not let JAVA_TOOL_OPTIONS slip in (as the JVM does by default)
 if not "%JAVA_TOOL_OPTIONS%" == "" (
-  echo "warning: ignoring JAVA_TOOL_OPTIONS=%JAVA_TOOL_OPTIONS%"
+  echo warning: ignoring JAVA_TOOL_OPTIONS=%JAVA_TOOL_OPTIONS%
   set JAVA_TOOL_OPTIONS=
 )
 
 rem JAVA_OPTS is not a built-in JVM mechanism but some people think it is so we
 rem warn them that we are not observing the value of %JAVA_OPTS%
 if not "%JAVA_OPTS%" == "" (
-  echo|set /p="warning: ignoring JAVA_OPTS=%JAVA_OPTS%; "
+  (echo|set /p=warning: ignoring JAVA_OPTS=%JAVA_OPTS%; )
   echo pass JVM parameters via ES_JAVA_OPTS
 )