Move signing and uploading to the release profile

protoc-artifacts/pom.xml

@@ -83,31 +83,40 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-gpg-plugin</artifactId>
-        <version>1.5</version>
-        <executions>
-          <execution>
-            <id>sign-artifacts</id>
-            <phase>verify</phase>
-            <goals>
-              <goal>sign</goal>
-            </goals>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>org.sonatype.plugins</groupId>
-        <artifactId>nexus-staging-maven-plugin</artifactId>
-        <version>1.6.3</version>
-        <extensions>true</extensions>
-        <configuration>
-           <serverId>sonatype-nexus-staging</serverId>
-           <nexusUrl>https://oss.sonatype.org/</nexusUrl>
-           <autoReleaseAfterClose>false</autoReleaseAfterClose>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
+  <profiles>
+    <profile>
+      <id>release</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-gpg-plugin</artifactId>
+            <version>1.5</version>
+            <executions>
+              <execution>
+                <id>sign-artifacts</id>
+                <phase>verify</phase>
+                <goals>
+                  <goal>sign</goal>
+                </goals>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.sonatype.plugins</groupId>
+            <artifactId>nexus-staging-maven-plugin</artifactId>
+            <version>1.6.3</version>
+            <extensions>true</extensions>
+            <configuration>
+               <serverId>sonatype-nexus-staging</serverId>
+               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+               <autoReleaseAfterClose>false</autoReleaseAfterClose>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
 </project>