Quote column name for summary post processor

[navis]

with column name 1.0

{
    "error": "Unknown exception",
    "errorMessage": "For input string: \"1.0sum\"",
    "errorClass": "java.lang.NumberFormatException",
    "errorStack": [
        "sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)",
        "sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)",
        "java.lang.Double.parseDouble(Double.java:538)",
        "io.druid.math.expr.ExprListenerImpl.exitDoubleExpr(ExprListenerImpl.java:95)",
        "io.druid.math.expr.antlr.ExprParser$DoubleExprContext.exitRule(ExprParser.java:110)",
        "org.antlr.v4.runtime.tree.ParseTreeWalker.exitRule(ParseTreeWalker.java:71)",
        "org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:54)",
        "org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:52)",
        "io.druid.math.expr.Parser.parse(Parser.java:188)",
        "io.druid.math.expr.Parser.parse(Parser.java:175)",
        "io.druid.query.aggregation.post.MathPostAggregator.<init>(MathPostAggregator.java:77)",
        "io.druid.query.aggregation.post.MathPostAggregator.<init>(MathPostAggregator.java:66)",
        "... more"
    ],
    "host": "metatron-web-05:8082",
    "serviceName": "druid/broker"
}

[navis]

Fixed