logo: fix curl-logo.svg, minimize SVGs more (#530)

- curl-logo: redo from original, to omit transparent border, and
  to restore original colors.

- apply more compression using svgcleaner 0.9.6 and svgo 4.0.0,
  then manual edit, indent by 1 space, add ending newline:
  - curl-logo: 8658 (=> 4918) bytes => 3348 bytes
  - curl-white-symbol: 2075 => 1593 bytes
  - curl-symbol: 2105 => 1623 bytes

Follow-up to 1fb4849 #522

Author: vszakats

logo/README.md

@@ -21,7 +21,7 @@ donated to the curl project on May 26 2016.
 | [curl-logo.ai](curl-logo.ai)                 | 1.6MB | vector     | AI              |
 | [curl-logo.jpg](curl-logo.jpg)               | 77K   | 2228 x 852 | JPEG            |
 | [curl-logo.png](curl-logo.png)               | 53K   | 2228 x 852 | PNG             |
-| [curl-logo.svg](curl-logo.svg)               | 4.9K  | vector     | SVG             |
+| [curl-logo.svg](curl-logo.svg)               | 3.3K  | vector     | SVG             |
 | [curl-logo.xcf](curl-logo.xcf)               | 168K  | 2228 x 852 | XCF             |
 | [curl-transparent.png](curl-transparent.png) | 10K   | 1970 x 656 | transparent PNG |
 
@@ -33,7 +33,7 @@ donated to the curl project on May 26 2016.
 |------------------------------------------------------------|------|------------|-----------------|
 | [curl-symbol.jpg](curl-symbol.jpg)                         | 37K  | 789 x 690  | JPEG            |
 | [curl-symbol.png](curl-symbol.png)                         | 24K  | 789 x 690  | PNG             |
-| [curl-symbol.svg](curl-symbol.svg)                         | 2.1K | vector     | SVG             |
+| [curl-symbol.svg](curl-symbol.svg)                         | 1.6K | vector     | SVG             |
 | [curl-symbol.xcf](curl-symbol.xcf)                         | 48K  | 789 x 690  | XCF             |
 | [curl-symbol-transparent.png](curl-symbol-transparent.png) | 3.0K | 683 x 571  | transparent PNG |