[SPARK-17378][BUILD] Upgrade snappy-java to 1.1.2.6

## What changes were proposed in this pull request?

Upgrades the Snappy version to 1.1.2.6 from 1.1.2.4, release notes: https://github.com/xerial/snappy-java/blob/master/Milestone.md mention "Fix a bug in SnappyInputStream when reading compressed data that happened to have the same first byte with the stream magic header (#142)"

## How was this patch tested?
Existing unit tests using the latest IBM Java 8 on Intel, Power and Z architectures (little and big-endian)

Author: Adam Roberts <aroberts@uk.ibm.com>

Closes #14958 from a-roberts/master.

dev/deps/spark-deps-hadoop-2.2

@@ -152,7 +152,7 @@ shapeless_2.11-2.0.0.jar
 slf4j-api-1.7.16.jar
 slf4j-log4j12-1.7.16.jar
 snappy-0.2.jar
-snappy-java-1.1.2.4.jar
+snappy-java-1.1.2.6.jar
 spire-macros_2.11-0.7.4.jar
 spire_2.11-0.7.4.jar
 stax-api-1.0.1.jar

dev/deps/spark-deps-hadoop-2.3

@@ -159,7 +159,7 @@ shapeless_2.11-2.0.0.jar
 slf4j-api-1.7.16.jar
 slf4j-log4j12-1.7.16.jar
 snappy-0.2.jar
-snappy-java-1.1.2.4.jar
+snappy-java-1.1.2.6.jar
 spire-macros_2.11-0.7.4.jar
 spire_2.11-0.7.4.jar
 stax-api-1.0-2.jar

dev/deps/spark-deps-hadoop-2.4

@@ -159,7 +159,7 @@ shapeless_2.11-2.0.0.jar
 slf4j-api-1.7.16.jar
 slf4j-log4j12-1.7.16.jar
 snappy-0.2.jar
-snappy-java-1.1.2.4.jar
+snappy-java-1.1.2.6.jar
 spire-macros_2.11-0.7.4.jar
 spire_2.11-0.7.4.jar
 stax-api-1.0-2.jar

dev/deps/spark-deps-hadoop-2.6

@@ -167,7 +167,7 @@ shapeless_2.11-2.0.0.jar
 slf4j-api-1.7.16.jar
 slf4j-log4j12-1.7.16.jar
 snappy-0.2.jar
-snappy-java-1.1.2.4.jar
+snappy-java-1.1.2.6.jar
 spire-macros_2.11-0.7.4.jar
 spire_2.11-0.7.4.jar
 stax-api-1.0-2.jar

dev/deps/spark-deps-hadoop-2.7

@@ -168,7 +168,7 @@ shapeless_2.11-2.0.0.jar
 slf4j-api-1.7.16.jar
 slf4j-log4j12-1.7.16.jar
 snappy-0.2.jar
-snappy-java-1.1.2.4.jar
+snappy-java-1.1.2.6.jar
 spire-macros_2.11-0.7.4.jar
 spire_2.11-0.7.4.jar
 stax-api-1.0-2.jar

pom.xml

@@ -159,7 +159,7 @@
     <scala.binary.version>2.11</scala.binary.version>
     <codehaus.jackson.version>1.9.13</codehaus.jackson.version>
     <fasterxml.jackson.version>2.6.5</fasterxml.jackson.version>
-    <snappy.version>1.1.2.4</snappy.version>
+    <snappy.version>1.1.2.6</snappy.version>
     <netlib.java.version>1.1.2</netlib.java.version>
     <calcite.version>1.2.0-incubating</calcite.version>
     <commons-codec.version>1.10</commons-codec.version>