Use HTTPS instead of HTTP for project attributes

Otherwise, Eclipse now yields errors like:

  Multiple markers at this line
  - cvc-elt.1.a: Cannot find the declaration of element 'project'.
  - schema_reference.4: Failed to read schema document 'bundleentry://260.fwk1924378583/xsd/maven-v4_0_0.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.

Unfortunately, the tidy-maven-plugin 1.1.0 reverts this change;
I filed mojohaus/tidy-maven-plugin#53 to correct the issue.

Author: ctrueden

pom.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="https://maven.apache.org/POM/4.0.0" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<groupId>org.scijava</groupId>